Chemistry topics, P

School Science Lessons
2024-12-26

Chemistry, P
Please send comments to: j.elfick@uq.edu.au
Contents
Pachycarpine
Pachypodol
Packaging gases
Paclitaxel
Paeonol
Paint Lead paint
Paint Red lead
Paint, (Safety)
Palladium, Pd
Palm oil, Palm kernal oil, (Table)
Palmatine
Palmitic acid
Palmitoleic acid
Paludolactone
Pampl's insect fixing solution, Prepare
Pancracine
Pancreatin
Pantothenic acid
Papain
Papanicolaou stain, Prepare
Papaverine
Paper chromatography, Separate, (Experiments)
Paper clips, rusting, (Experiment)
Parabens
Paracetamol
Paracresol
Paradichlorbenzene
Paraffin oil, kerosene, (Experiment)
Paraldehyde
Paramethyl red, acid-base indicator
Paranitrophenol, acid-base indicator
Paraquat, (Agriculture)
Parchment
Paris Green, Copper (II) acetoarsenite
Parthenolide
Particles of matter, Diffusion
Particles, Suspensions
Particles, Size, (Experiments)
Particles, Surface / volume ratio
Parts per million, (Measurement)
Pascal, SI derived units
Pasteurization of milk
Pasteurized milk test, (Experiment)
Patchoulol
PBDE, Pentabromodiphenyl ether
PCBs, Dioxins, Agent orange
Pectin, (Experiments)
Pedalitin
Peganine
Pegmatite, (Geology)
Peimine
Pelargonidin
Pelargonin
Pelletierine
Peltier effect, (Experiments)
Pencil, "Lead pencils", (Geology)
Pencil sharpener, Mg, (Experiment)
Penicillium, penicillin
Pennyroyal
Pentan
Pentane, C5H12
Pentobarbital, Barbiturates
Pentosans
Pentose, 5 C
Pentyl
Peonidin
Pepper, (Experiments)
Pepsin, (Experiments)
Peptides, (Experiments)
Peptone
Percentage solutions
Perchloric acid
Perfluoroalkyls, PFAS
Perfluorooctanoic, PFOA
Perfluorooctanesulfonic acid, PFOS
Perfume, Volatility of different liquids
Perfume, Perfumes and smells, (Experiments)
Periclase, MgO, (Experiments)
Perilla ketone
Perindopril
Perillaldehyde
Perillartine
Perillene
Perillyl alcohol
Periodic acid
Periodic table
Perlolyrine alkaloid
Perlon plastic, Nylon polyamide
Permalloy bar
Prepare chemicals
Permanent wave solution, (Experiments)
Permanganate ion
Permanganates, hazards
Permeate (cheese), (Experiments)
Permethrin
Permitted in schools
Perovskite
Peroxides, Hazards
Persistence, (Agriculture)
Peru balsam, Prepare
Plagioclase feldspars, (Geology)
Pesticides, (Agriculture)
PET, Birefringent clear plastics, (Experiments)
Petasin
PETE, Plastics recycling code
Petrol sniffing
Petrolatum, "Vaseline", (TN)
Petroleum, (Experiments)
Petroselenic acid
Petunidin
Pewter
PFAS chemicals
PFOA, Perfluorooctanoic acid
PFOS, Perfluorooctanesulfonic acid
pH tests, (Experiments)
Phase
Phaseolic acid
Phellandrene
Phenanthroline
Phenethyl alcohol
Phenethyl isothiocyanate
Phenethylamine
Phenobarbital, Barbiturates
Phenol
Phenols, phenolics
Phenol red, acid-base indicator
Phenolic compounds by name
Phenols, by number of Carbon atoms
Phenolphthalein, acid-base indicator
Phenothiazine, PTZ
Phenoxyethanole
Phenyl group, (C6H5-)
Phenylalanine
Phenylamine, Aniline
Phenylamine, Prepare
Phenylpropanoids
Phenylpropanolamine
Phillyrin
Phloroglucinol
Phloxine
Phosgene, carbonyl chloride
Phosphates, (Experiments)
Phosphatidylcholine group, Lecithins
Phosphine
Phospholipids, phosphoglycerides, (Experiment)
Phosphoric acid
Phosphorus, (Experiments)
Phosphorus compounds, (Experiments)
Phosphorescence
Phosphorylation, (Experiments)
Photochemical reactions, (Experiments)
Photography, (Experiments)
Phthalic acid, Phthalates
Phthaleins, Fluorescein
Phycobilins
Phycobiliproteins
Phyllalbine
Phyllanthin
Phyllanthostatin
Phyllodulcin
Phytoalexins
Physics, Laboratory safety for physics teaching
Physics, Physical changes and chemical changes, (Experiments)
Physical hazards, (Safety)
Physcion
Physcion 8-glucoside
Physostigmine
Phytochemicals
Phytochromes
Phytolaccoside
Phytoene
Phytofluene
Phytosterols
Piceatannol
Piceid
Picrates
Picric acid
Picrocrocin
Picrotoxin
PIDCP, Tests for vitamin C, (Experiments)
Piezoelectric, (Experiments)
Pig iron, cast iron
Pigment names
Pigments, (Experiments)
Plant dyes, Prepare, (Primary)
Plant extracts acid-base indicators
Pilocarpine
Pimpinellin
Pinocembrin
Pindone
Pinene
Ping-pong ball, Ignite, (Experiment)
Pinitol, Cyclitol
Pinocamphone
Piped gas, "lab gas"
Piperidine
Piperine
Piperitone
Piperonal
Pipernonaline
Piperonyl butoxide
Pipettes
Piplartine
Pitch, (Chemistry)
Pitchblende, Uraninite, (Geology)
pKa, Strong and weak acids
Placer deposits, (Geology)
Plagioclase feldspar, (See: Group 2.)
Plantamajoside
Plant extracts
Plant gall ink
Plant oils
Planteose
Plastics
Perlon plastic, Nylon polyamide
Plaster of Paris, (Experiments)
Plasticine, modelling clay
Plastics manufacture
Plastics recycling code
Plating, Electroplating
Platinum, Pt, (Experiments)
Pleuran
Plumbagin
Plutonium
PMMA
Podophyllotoxin
Poisons and First Aid, (Table)
Poisons, Chemical Pesticides
Poisson's ratio, v, (rubber hose), (Experiment)
Polarization, Polaroid film
Pollution, Environmental chemistry, (Air, Water)
Polonium, Po
Perlon plastic, Nylon polyamide
Polymers
Polymer prefix, Chemical names beginning Poly-
Poncirin
Pools, Swimming pool chemistry
Porcelain, laboratory items
Porphyrins, haemoglobin
Porphyry, (Geology)
Portland cement
Portolacaxanthin
Potash Potassium oxide, K2O
Potassium
Potential energy, Chemical potential energy, enthalpy
Poultices, Prepare
Pozzolana, (Geology)
PP, Plastics recycling code
18.5.1 Parts per million
Practical work, student learning
Praseodymium, Pr
Prebetanin
Precious metals
Precipitates, (Experiments)
Prednisolone
Prefixes and suffixes, Chemistry
Prefixes, SI prefixes
Prenol
Prenylnaringenin
Prepare chemicals
Preservatives, food additives
Preserving food, Food preservation
Pressure, (Physics)
Prilled
Proactinium, Pa
Producer gas
Progoitrin
Prohibited High Risk Chemicals
Proline, (Table of amino acids)
Proline, DNA codons
Promethazine
Promethium, Pm
Pronuciferine
Proof spirit, Degrees proof
Prop-2-enal, acrolein
Propan-1,2-diol, propylene glycol
Propanal, propionaldehyde
Propane C3H8
Propanethiol, Propane-1-thiol
Propane-1,2,3-triol, Glycerol, glycerin, glycerine
Propanedioic acid, malonic acid, C3H4O4
Propanoic acid, propionic acid, C3H6O2
Propanol
Propanone, acetone
Propellants, packaging gases, food additives
Propyl bromide, 1-bromopropane
Propyl gallate
Propylamine, amine
Propylene glycol, antifreeze
Proscillaridin A
Prosopinine
Protease, (Microbiology)
Protective clothing, equipment, (Safety)
Proteins, (Experiments)
Protoalkaloids
Protocatechuic acid
Protonated
Protopine
Protostephanine
Protoveratrine
Prunetin
Prunasin
Prussian blue, iron (III) ferrocyanide
Pseudoalkaloids
Pseudoephedrine
Pseudohypericin
Psoralen
PS, Plastics recycling code
Psicose
Psilocin
Psilocybin
PTC, phenylthiocarbamide, (Experiment)
Phenylthiourea solution, Prepare
PTFE, Polytetrafluoroetheylene, "Teflon"
Puerarin
Pulegone
Pumice, (Geology)
Pumpkin seed oil, Dichromatism
Pure substances, Separate pure substances from mixtures, (Experiments)
Purpureacin
Purine
Putrescine
Prepare putty
Pyrazine
Pyrene, Reactions of benzene, (Experiments)
Pyrethrin, (Agriculture)
Pyrex, Borosilicate glass
Pyridine
Pyridine-3-carboxylic acid, nicotinic acid, niacin
Pyridoxine
Pyrimidine, Nucleosides, nucleic acids, DNA, RNA
Pyrite, iron (II) sulfide, (Experiments)
Pyrite, (Geology)
Pyroelectricity, ferroelectricity, (Geology)
Pyrocatochuic acid
Pyrogallol, (Experiments)
Pyrolusite, manganese (IV) oxide
Pyrolysis
Pyromorphite, (Geology)
Pyrophoric liquids
Pyrophoric solids
Pyroxylin, Collodion, cellulose nitrate
Pyrrhotite, iron sulfide, (Geology)
Pyrrole
Pyrrolidine and Piperidine Alkaloids
Pyrrolizidine alkaloids
Pyrrolidine
Pyrrolines
Pyruvic acid

Pachypodol
Pachypodol, C18H16O7, a trimethoxyflavone, anti-emetic
It occurs in Korean mint, (Agastache rugosa), Combretum quadrangulare, and in Euodia elleryana.

Palladium, Pd
See Palladium Table of Elements
See Palladium, RSC
Palladium, Pd (Greek Pallas (Athene) goddess), white metal, hard, ductile, transition metal, free element, similar to silver. was called "new silver".
It was used for contact points for flintlock pistols, boiling vessels and crucibles.
Now used as foil, powder and wire, in low voltage electrical contacts, and as catalysts for organic chemical synthesis and carbon bond forming reactions, e.g. C-C.
It is a lustrous silver-white metal.
It is resistant to corrosion in air and acids, but is attacked by hot acids, and dissolves in aqua regia.
It can absorb up to 900 times its own volume of hydrogen.
Iy is used in jewellery as "white gold" alloys with platinum.
It is now the main ingredient of catalytic converters to reduce emissions from car exhausts, replacing platinum.
Also, it is used in wide screen televisions, computers and mobile phones, as tiny multi-layer ceramic capacitors.
Atomic number 46, Atomic mass 106.42 g. mol-1, Density 11.9 g.cm-3 at 20C
M. P, 1560 oC, 9 isotopes, Standard electrode potential + 0.85 V (Pd2+/ Pd )
Palladium (II) acetate, Palladium (II) chloride, Palladium AAS Solution

Palmitic acid
Palmitic acid, CH3(CH2)14COOH, saturated fatty acid, hexadecanoic acid, cetylic acid
It occurs in olive oil, coconut oil and palm oil.
Palmitic alcohol, hexadecanoic, cetyl alcohol, 1-hexadecanol, CH3(CH2)15OH
Palmityl alcohol, CH3(CH2)14CH2OH, hexadecanol

Palmitoleic acid
Palmitoleic acid, C16H30O2, CH3(CH2)5CH=CH(CH 2)7COOH, irritant, unsaturated fatty acid, carboxylesterase inhibitor
It occurs in glycerides of human adipose tissue, and in human blood serum.
It is possibly anti-thrombotic to prevent stroke.
It occurs in: Macadamia integrifolia

Pancreatin
Pancreatin (commercial product), is an alcohol extract of hog pancreas used as enzyme replacement therapy.
Pancreatin contains pancreatic enzymes, trypsin, amylase, and lipase, and is used as a digestive aid.
Pancreatin is used to replace digestive enzymes when the body does not have enough of its own.
9.2.5 Digestion in the intestines, pancreatin suspension

Pancracine
Pancracine, C16H17NO4 an isoquinoline alkaloid , occurs in Pancratium maritimum, and Amaryllis belladonna

Pantothenic acid
Pantothenic acid, C9H17NO5, vitamin B5, the D-isomer is a water-soluble essential nutrient in most food, especially egg yolks, sunflower seeds, blueberries, mulberries, cherry tomatoes.
Pantothenic acid, an antioxidant, is a component of coenzyme A (CoA) and a part of the vitamin B2 complex, growth factor essential for many metabolic functions and synthesis of cholesterol, steroid hormones, and other biochemicals.
Calcium pantothenate, C18H32CaN2O10, is used as a stable dietary supplement.
19.2.5 Freezing, thawing and cold storage of meat
13.12 Nutritional value of eggs

Paracetamol
Paracetamol, C8H9NO2, CH3CONHC6H4OH, acetaminophen, 4-Acetamidophenol, Tylenol, odourless, white crystalline solid, bitter taste. aqueous solution pH 6
It is a non-narcotic, antipyretic, anti-inflammatory, the most commonly taken analgesic, and helps to reduce fever.br> It occurs in varios forms including effervescent tablets and in other medications where dosage may vary.
The suggested dose of paracetamol for adults and children 12 years and over is: no more than 1g every 4 to 6 hours, a total of 4g daily

Paraldehyde
Paraldehyde, C6H12O3, colourless liquid, hypnotic, sedative, anticonvulsant, but seldom used, because administration difficult, so now a former sedative.

Parchment
Parchment, treated animal skin, (French parchemin, pergumin, writing material)

Patuletin
Patuletin, C16H12O8, (6-Methoxyquercetin), Quercetagetin 6-methyl ether, Trimethoxyflavone, antioxidant, analgesic, lipoxygenase inhibitor,
It occurs in German camomile, pigment from flowers of French marigold, Tagetes patul.

Pectin
Pectin is a heteropolysaccharide from the cell wall of higher plants.
It is composed of linked methylated polygalacturonic acid units.
Pectin qualifies as a generally recognized as safe food substance, which allows it be used with no food limitations.
16.1.9 Pectin
4.3.2 Pectins and pectinases
Pectins, E440, Emulsifiers, food additives
16.5.8, Tests for pectin in jelly and jam

Pedalitin
Pedalitin, C16H12O7, flavone, tetrahydroxyflavone, monomethoxyflavone, xanthine oxidase inhibitor, inhibits lipogenase
It occurs in Eremosparton songoricum, Rabdosia japonica, Ruellia tuberosa, sesame Sesamum indicum, and in Sullivantia.

Pelargonidin
Pelargonidin, C15H11O5, an anthocyanin, (produced from flavylium,C15H11O+, grape skin extract), orange pigment
It occurs in human gut microbiota, berries, kidney beans, Philodendron, snapdragon (Antirrhinum majus)

Pelargonin
Pelargonin, C27H31O15, pelargonidin, (3,5-di-beta-D-glucoside), anthocyanin
It occurs in Mukul myrrh tree, (Comiphora mukul).

Pentan
Pentan-1-ol, colourless liquid, bad smell
Pentan-1-ol, C5H12O, 1-pentanol, n-amyl alcohol, n-amyl alcohol, normal amyl alcohol, toxic, Flammable
Pentan-1-ol, Solution < 25%, Not hazardous
Pentan-2-ol, C5H12O, 2-pentanol, sec-amyl alcohol, n-pentyl alcohol, toxic by all routes, Flammable
Pentan-2-one, methyl propyl ketone, toxic by all routes, Highly flammable
Pentan-3-one, diethyl ketone, toxic by all routes, Highly flammable

Pentyl
Pentyl -(C5H11)
Pentyl alcohol, C5H11OH, pentan-1-ol (amyl alcohol, n-pentyl alcohol)
Pentyl butyrate, n-amyl butyrate (apricot odour), moderate flammability
Pentyl ethanoate, C5H12O, n-amyl acetate, normal amyl acetate, pentyl acetate, 1-pentanol
Pentyl propanoate, n-amyl propionate, Highly flammable
Prepare amyl acetate, (pear oil): 16.3.7, n-pentyl acetate

Peonidin
Peonidin, C16H13O6, anthocyanin
It occurs in Lowbush blueberry (Vaccinium angustifolium).
Peonidin chloride, C16H13ClO6, anthocyanidin chloride, antineoplastic, apoptosis induce, antioxidant

Pepper
Pepper, black pepper, spice, Piper nigrum
Black pepper, (Piper nigrum), "pepper", commercial pepper
31.2.7 Separate pepper from salt and pepper, jumping pepper
Sprinkle salt on water, surface contracts momentarily towards crystals, opposite with pepper.
Use pepper, black pepper, around skirting boards before carpeting to deter silverfish.

Chilli Project
Chilli pepper, Capsicum annuum, Solanaceae
In the U.S. the Capsicum species are called "peppers".

Peptides
Peptides have amino acids linked in a linear sequence, where the carboxyl group of a amino acid is linked to the amino group of the next amino acid.
A covalent bond forms between the carbonyl carbon of a amino acid with the nitrogen atom of the next amino acid, with the loss of water.
Peptides include structures formed from α-amino acids and from any amino carboxylic acid.
Natural peptides include oxytocin (uterus contraction hormone and stimulates lactation), and insulin (pancreatic hormone).
ATP, adenosine triphosphate: 16.2.4
Blood constituents (humans): 9.1.2
Construct molecular models: 11.2.3
Glycoproteins and glycolipids: 16.2.2
LSD (lysergic acid diethylamide): 5.5.18
Tests for proteins, biuret test: 9.4.2
Tests for proteins, heat test for proteins: 9.4.4

Peptone
Peptone is a soluble protein formed during protein breakdown in the digestive tract
Peptone is a water-soluble mixture of polypeptides and amino acids from partial hydrolysis of protein, e.g. beef peptone
Peptone: Peptone

Perchloric acid
Perchloric acid, HClO4, ClHO4, chloric (VII) acid, 70% W/W (strong acid), clear, colourless, odourless aqueous solution, toxic by all routes.
Perchloric acid, strong oxidizing agent if hot, spontaneous explosion of soaked wood, explosive mixture with combustibles or organic compounds
It is corrosive to metals and tissues, closed containers may rupture. violently if heated.
Perchloric acid should not be used or stored in a school science laboratory.
Perchlorates, (ClO4-)
Storing oxidizing agents: 3.7.8.

Periodic acid
Periodic acid, HIO4 and H5IO6, toxic by all routes, explosive mixture with combustibles or organic compounds.
ACS reagent, 100 g in glass bottle

Periodic Table
See Periodic Table (Modern Teaching Aids)
Introduction to the periodic table: 1.10.1
Oxides and the periodic table: 12.13.5
Patterns in the periodic table: 1.10.2
Periodic table: Table 1
Periods: 1.11.0

Permanganate ion
Permanganate ion, manganate (VII) ion, (MnO4-)
Permanganates have purple colour and are soluble in water, noncombustible.
They accelerate burning of combustible material, especially finely divided material when permanganates may spontaneously ignite.
Contact of permanganates with sulfuric acid may cause fire or explosion.

Permethrin
Permethrin, C21H20Cl2O3, ester, pale brown liquid. Relatively water insoluble, sold as: "Nix, Ambush, Pounce, Transpermethrin"
Pyrethrins occur in pyrethruµm extract from chrysantheµmuµm flowers.
The pyrethrins are used in household insecticides and products to control insects on pets or livestock.
Pyrethroids are similar manufactured chemicals, which are ore toxic and last longer in the environment.

Permitted in schools
Quantity of chemical to be used in experiments: 3.4.2, (5 mL of solution, or ...)
Chemical residues3.3.0
Chemical Safety
Chemical Standards National Formulary, NF
Chemical vapours and smelling chemicals3.4.8
Prohibited High Risk Chemicals

Petroleum
Petroleum, petrol, gasoline, "gas", Highly flammable, toxic by all routes.
Do not inhale vapour and do not use petrol as a paint "thinner".
Distil crude oil and collect the fractions: : 10.3.9
Fractional distillation of crude oil: 16.8.0
Petrol, "gas", gasoline, motor fuel: 16.8.9
Petroleum (crude oil and gas): 35.3.10, (Geology)
Petrol-sniffing (Abuse of volatile substances): 5.5.2
Petroleum-based spray oils, + emulsifying agent, horticultural oils, block insect spiracles, e.g. "PestOil"
Petroleum ether, Cleaning agents, solvents: 2.3.7
Petroleum gas; 16.8.10
Petroleum fraction: 7.9.41
Petroleum spirit: 7.9.41.1
Separate by fractional distillation: 10.3.6
Petroleum jelly, "Vaseline", petrolatum

Petroselenic acid
Petroselenic acid, C18H34O2, (6-Octadecenoic acid), irritant, and is used as a major seed oil constituent.
It occurs in parsley Petroselenium crispum seed, Agaricus blazei, and Angelica ternata.

Petunidin
Petunidin, C16H13O7+ , Petunidol anion, an O-methylated anthocyanidin
It occurs in Aronia, Amelanchier alnifolia, Vitis vinifera, Vitis rotundifolia, Vicia faba, petal colours, and in sweet pea (Lathyrus odoratus).
Petunidol chloride, C16H13ClO7, anthocyanidin chloride, petunidin is the cationic component.

Pewter
Pewter, malleable, alloy of mostly Sn, + some Cu, Sb, and Bi, previously used for cheap mugs and dishes.

pH tests
Acid-base indicators
Change in pH near the equivalence point: 12.2.2
pH: 12.3.6
pH of salt solutions: 12.10.7
pH of solid acids: 19.1.11
pH of swimming pools: 18.3.0
pH soil test: 6.10.7, (Soils)
Prepare acid-base indicators: 5.6.2
Prepare acid-base plant extract indicators: 5.6.3
Soil acidity, tests for soil pH: 6.1.0
Tests for pH of the environment: 18.1.0
Tests with multiple reagent strips: 19.5.6, (See: pH tests)

Phase
7.9.15 Phase, Continuous phase / outer phase
24.10.0 Phase changes, liquid / solid, M P, and F P
24.11.0 Phase changes, liquid / gas, boiling point, B P

Phaseolic acid
Phaseolic acid, C13H12O8, phenylpropanoid, an oxybutanedioic acid, hydroxycinnamic acid
It occurs in Phaseolus vulgaris leaves, in Trifolium pratense, in Raphanus sativus.
Phaseolin, C20H10O4, phytoalexin, occurs in Phaseolus vulgaris, French bean, Fabaceae, and in the stems of Erythrina species.

Phytoalexins
Phytoalexins are toxic substances, usually isoflavonoids or terpenoids, produced in plants only after stimulation by pathogenic fung, bacteria, and nematodes.
The phytoalexins are produced by healthy cells near damaged cells in response to substances diffusing from the damaged cells.
Phytoalexins include: | Phaseollin, C20H10O4 in bean | Pisatin, C17H14O6 in pea | Glyceollin, C20H18O5, in soybean | Rishitin, C14H22O2 in potato | Gossypol, C30H30O8 in cotton | Capsidiol, C15H24O2 in pepper |.

Phenanthroline
1,10-phenanthroline monohydrate, use in fume cupboard or < 10 g in cross ventilation (redox indicator), toxic
1,10-phenanthroline iron complex, ferroin solution (redox indicator), toxic if ingested
1,10-phenanthroline iron complex, [10-phenanthroline with iron (II) salt], purchase already diluted solution

Phenethyl alcohol
Phenethyl alcohol, C8H10O or C6H5CH2CH2OH, benzeneethanol, benzyl carbinol, phenol, benzene, primary alcohol, irritant
It is used as a fragrance in rose perfume, plant growth retardant, antimicrobial, antiseptic, disinfectant, aromatic essence and preservative in pharmaceutics.
It occurs in almond flavouring ingredient, in ylang-ylang oil, in citrus essential oils, in Zanthoxylum, in Rosa rugosa, in Pinus, in Piper longum, in Populus.

Perovskite
Perovskite, calcium titanate mineral, CaTiO3, used in newer solar cells, (Geology)

Phenylpropanolamine
Phenylpropanolamine, (PPA). Norephedrine, β-hydroxyamphetamine, C9H13NO, irritant, stimulates release of norepinephrine.
It acts in the mucosa of the respiratory tract causing vasoconstriction and reduction in swelling of nasal mucous membranes.
It is used as a decongestant and appetite suppressant, formerly in commercial cough and cold medicine, but no longer used in USA and Canada.
β-hydroxyamphetamine has 4 isomers,d- and l-norephedrine and d- and l-norpseudoephedrine.
d-Norpseudoephedrine is Cathine, and it occurs in Catha edulis (khat).

Phenyl salicylate
Phenyl salicylate, C13H10O3, phenyl-2-hydroxybenzoate, salol, toxic if ingested, flammable.
Phenyl salicylate is prepared by heating salicylic acid with phenol It is used in experiments to show cooling rates affect crystal size.
It was formerly in sunscreens.

Phenylalanine
Phenylalanine, C9H11NO2, L-phenylalanine, a phenylpropanoic acid, odourless white crystalline powder, slightly bitter taste
Phenylalanine is an essential aromatic amino acid and is a precursor of melanin, C18H10N2O4.
Phenylalanine, DNA codons
Phenylalanine, sweetener: 19.2.6
Phenylalanine (Table of amino acids)
Phenylalanine, DNA codons

Phenoxyethanol
Phenoxyethanol, C8H10O2, ethylene glycol monophenyl ether, colorless oily liquid. faint aromatic pleasant odour
It is used as a perfume fixative, insect repellent, antiseptic, solvent, preservative, to inactivate bacteria, and yeast, and a fish anesthetic!
It is the most commonly used preservative in personal care formulations. sunscreens, and cosmetics.
It occurs in green tea and it is produced chemically by: phenol + ethylene oxide (EU)

Phloroglucinol
Phloroglucinol, C6H6O3, (1,3,5-trihydroxybenzene), harmful if ingested, corrosive to skin
It is used as wood stain.
It occurs in Cytospora ceratosperma, and Humulus lupulus.
Prepare phloroglucinol solution: 7.35

Phosphine
Phosphine, PH3, gas, colourless, flammable, high toxic, rotten fish garlic smell, silicon solid state device doping agent, grain insecticide "QuickPhos"
It occurs in marsh lights, (will-o'-the-wisp), from decayed organic matter.
Diphosphane, P2H4

Phosphorescence
Europium, Eu
14.03 Fluorophores
Merbromin, C20H8Br2HgNa2O6
Phosphorescence
Terbium, Tb, Phosphorescence

Phosphorus, P
See Phosphorus Table of Elements
See Phosphorus, RSC
Phosphorus, P, (Greek phōsphoros, light-bringing), non-metal, allotropes, white waxy solid, in minerals and organisms.
It occurs mainly as phosphates and in many minerals, e.g. apatite.
Phosphorus has 2 main allotropes:.
1. White phosphorus, yellow phosphorus, translucent, white-yellow, very reactive, poisonous, not permitted in schools.
2. Red phosphorus, high mp. low reactivity, low toxicity.
Phosphorus-32, reactor-produced medical radioisotope, half-life 14.28 days, used to treat excess red blood cells.
Phosphates are important agricultural fertilizers, e.g. the P in NPK fertilizer.
Phosphorus occurs as inorganic calcium phosphate in bones and teeth, in tissue and in the ATP molecule, and in urine.
The recommended daily allowance, RDA, is 1200 mg.
Phosphoric acid, H3PO4, behaves as a tribasic acid, although the normal salts are much hydrolysed in solution.
Phosphorescence is the green glow from the slow oxidation of white phosphorus and is an example of chemiluminescence.
Reactions of phosphorus, P: 12.9.0
Phosphorus compounds
Phosphorus deficiency in soils: 6.12.4
Phosphorus deficiency: 1.11.0
Phosphorus soil tests, Bray test and Colwell test: 1.11.0
DEA list of chemicals: 3.9.5 (See: phosphorus)
Red phosphorus, P4
Phosphorescence
Red phosphorus, safety matches: Matches
White phosphorus, P4

Phosphorus compounds
See diagram 16.1.1h Propylcyclopentane
Reactions of phosphorus compounds: 12.9.0
Decomposition of phosphates: 3.7.16
Detergent phosphates: 12.5.4
Diphosphane, P2H4
Matches, safety matches
Organophosphates and carbamate insecticides: 4.5b
Phosphates
Phosphine, PH3
Phosphoric acid
Phosphorous compounds, organophosphorus insecticides: 16.7.14
Phosphorus oxychloride, phosphoryl chloride, Highly toxic by all routes
Phosphorus oxychloride, Solution / mixture < 5%, Not hazardous
Phosphorus pentachloride with water: 12.19.8.8
Phosphorus sesquisulfide, P4S3, yellow solid, in "strike anywhere" matches
Phosphorus tribromide, phosphorus (III) bromide, Highly toxic by all routes, Highly corrosive
Phosphorus tribromide, reacts with moisture to form toxic fumes and heat, so use in fume cupboard or small quantities in cross-ventilation
Phosphorus tribromide, Solution / mixture <5%, Not hazardous
Phosphorus trichloride with water: 12.9.8
Phosphorus (V) chloride
Phosphorylation
Phosphonates, Ethephon: 4.4.8
Phosphonates, Glyphosate: 4.4.9
Prepare microcosmic salt: 12.9.1
Reactions of phosphites, HPO32-: 12.9.5
Reactions of phosphorus and phosphates: 12.9.6
Phosphorus (III) chloride
Phosphorus pentoxide
Superphosphate production: 12.14.5
Tests for phosphate ions in water: 18.4.1
Tests for phosphates: 12.11.15
Phosphorescence(Experiments)

Phosphates
Phosphate ion, PO43-
Ammonium phosphate, (NH4)3PO4, triammonium phosphate (V)-3-water, ammonium phosphate tribasic, nitrogen and phosphorus garden fertilizer, flame retardant, added to baking powders to promote yeast growth.
Ammonium sodium hydrogen phosphate (V)-4-water, Na(NH4)HPO4.4H2O, ammonium sodium hydrogen orthophosphate, microsmic salt (from urine).
Ammonium sodium hydrogen orthophosphate, Na(NH4)HPO4.4H2O, microsmic salt (from urine)
ATP, adenosine triphosphate: 16.2.4
Bone phosphate: E542
Calcium phosphate
Chromium (III) phosphate, CrH8O8P, Chromium (III) phosphate tetrahydrate
Decomposition of phosphates: 3.30.13
Detergent phosphates: 12.5.4
Detergents use polyphosphates or zeolite to make calcium inactive in the system
Diammonium phosphate, diammonium hydrogen phosphate (DAP) (NH4)2HPO4
Food additives: 19.4.4 (Search,phosphate, e.g. Potassium phosphates: E340)
Group tests for phosphorus and phosphates: 12.13.0
Inorganic builders in washing powders: 12.6.8
Monoammonium phosphate (MAP)
Monopotassium phosphate (MKP)
4.3.4 "Yates Anti Rot Phosacid", (Agriculture)
Phosphate buffer reagent: 9.2.25
Phosphate ions in water: 18.4.1
Phosphates, essential for development of bones and teeth, genetic material
Phosphates hazards: 3.7.14
Phospholipids (phosphoglycerides): 16.3.3.0.1
Phosphorylation means adding a phosphate group to a molecule
Phosphorous compounds, organophosphorus insecticides: 16.2.6
Prepare solutions: 3.0
Reactions of phosphorus and phosphates: 12.13.1
Remove water hardness: 12.2.5
Soaps and synthetic detergents, "syndets": 12.5.1
Sodium acid pyrophosphate food grade
Sodium dihydrogen phosphate (V)
Sodium hexametaphosphate (SHMP)
Sodium tripolyphosphate (STPP), Na5P3O10
Soil-less culture, Knop's, hydroponics,9.9.18.3
Struvite mineral, (NH4)MgPO4.6H2O, ammonium magnesium phosphate
Superphosphate production: 12.14.5
Teeth and toothpaste, calcium hydroxyapatite: 9.226
Tests for phosphate ions in water: 18.4.1
Tests for phosphates: 12.11.15
Tetrapotassium pyrophosphate (TKPP )
Trisodium orthophosphate
Na3PO4 (TSP), "sodium phosphate": E339
Urea phosphate, UP, CH7N2O5P, urea phosphoric acid

Phosphoric acid
Phosphoric acid, H3PO4, orthophosphoric acid, phosphoric (V) acid, crystalline, as solution is colourless, odourless liquid, conc. 14.7.M, RD 1.71 to 1.75
It is miscible with water and ethanol, "Kill-rust", E33, weak acid, or, white rhombic solid, 85% W /W, 90% W / W, toilet bowl cleaner.
Phosphoric acid is prepared in industry by heating calcium phosphate rock with sulfuric acid, prepare by red phosphorus with nitric acid.
Low cost from hardware stores, rust remover, e.g. "Naval Jelly", "Killrust", or, for cleaning concrete, from brewing suppliers, from hydroponics suppliers.
Phosphoric acid sequestering agent binds divalent cations, including Fe++, Cu++, Ca++, and Mg++.
Phosphoric acid, concentrated, 16 M, 95%, Phosphoric acid 85% min food grade 130 mL of concentrated solution for 1 litre of 2 M solution
Phosphoric acid, > 4 M (72%) (may be supplied as 85%) (used in rust converters), toxic. Highly corrosive to skin
Phosphoric acid, < 4 M (72%), > 2 M (36%), toxic. Highly corrosive to skin
Phosphoric acid, < 2 M (36%), > 0.5 M (10%), toxic. skin irritant
Phosphoric acid, < 0.5 M (10%), Not hazardous, but do not ingest
Phosphoric acid, ionization reaction: 12.3.7
Ionization reaction:
H3PO4 + H2O < --> H3O+ + H2PO4-
H2PO4- + H2O < --> H3O+ + HPO42-
HPO42-+ H2O < --> H3O+ + PO43-

Phosphorus (III) chloride
Phosphorus (III) chloride, PCl3, phosphorus trichloride, + water --> phosphorous acid, H3PO3
Phosphorus (V) chloride PCl5, garlic-like odour, very soluble in water
Prepare phosphorus trichloride, PCl3: 12.19.2

Phosphorus pentoxide
Phosphorus pentoxide, P2O5, phosphoric anhydride, P4O10, phosphorus (V) oxide, phosphoric oxide, white powder, hexagonal crystals, deliquescent, thermoluminescent, toxic by ingestion, highly corrosive.
Prepare nitrogen gas: 3.46
It reacts violently with water to form phosphoric acid, liberating a large amount of heat, reacts violently with iodides.
With sodium and potassium metals ignition on contact.
With formic acid forms highly toxic carbon monoxide gas.
It is used as a dehydrating agent.
The crust on the surface of old samples is mostly phosphoric acid, but remove it before using the phosphorus pentoxide beneath.
Prepare phosphorus pentoxide: 12.13.3.1

Phosphorylation
Phosphorylation is when a phosphate molecule is added to an organic compound.
For example: adenosine diphosphate (ADP) + Phosphate --> adenosine triphosphate (ATP)
Phosphorylation means adding a phosphate group to a molecule.16.3.5.2.1
ATP, adenosine triphosphate: 16.2.4
Tests for glucose, urine test: 19.1.31
Tetrapyrroles, bilin, bilirubin, biliverdin, haeme: Tetrapyrroles

Phosphorus (V) chloride
Phosphorus (V) chloride, PCl5, phosphorus pentachloride, light yellow colour, + hot water --> ortho-phosphoric acid, H3PO4
Phosphorus (V) chloride, PCl5, phosphorus pentachloride
Phosphorus (V) chloride, phosphorus pentachloride, Highly toxic by all routes, highly corrosive
Phosphorus (V) chloride, Solution / mixture < 5%, Not hazardous: 9.6.1.1
Prepare phosphorus pentachloride, PCl5: 12.13.3

Photochemical reactions
"Sun Blueprint Paper", photochemical reactions (toy product)
Chloramines in swimming pools: 18.1.5
Chlorofluorocarbons, CFCs, "Freons": 12.19.5.0
Ozone and photochemical smog: 3.50.1
Photolysis: 7.9.42

Photography
Silver chloride precipitate in photography: 7.8.7.1
Photography, Reactions of silver halides: 12.19.4.0
Photography wastes, Disposal: 15.1.9.1

Phyllanthin
Phyllanthin, C24H34O6, lignan, bitter taste, in Phyllanthus niruri leaves

Phyllanthostatin A
Phyllanthostatin A, C29H30O13, phyllanthocide, lignan, cytostatic, in Phyllanthus acuminatus

Phloxine B
Phloxine B, antibacterial fluorescent dye, (2,4,5,7-Tetrabromo-4,5,6,7-tetrachlorofluorescein disodium salt)

Phytolaccoside B
Phytolaccoside B, C36H56O11, esculentoside B, , triterpenoid saponin, anti-rheumatic, anti-inflammatory
It occurs in pokeweed, Phytolacca americana.

Picric acid
Picric acid, C6H3N3O7, C6H2(NO2)3OH, (2,4,6-trinitrophenol), trinitrophenol, carbazotic acid, toxic. skin irritant.
It is Not permitted in schools.
Picric acid, yellow crystals stain skin yellow.
Explosive when dry and compacted.
Do not open bottles, because crust may explode.
Picric acid, (stains yellow, unstable explosive. used in Gram stain and Bouin's picro-formol preservative solution.
Picrates, salts of picric acid (2,4,6-trinitrophenol)

Piceid
Piceid, C20H22O8, stilbenoid glucoside, polydatin, stilbene in medicinal herbs, antioxidant, anti-inflammatory, neuroprotective.
It occurs in grape juice, in Picea sitchensis, in Polygonum cuspidatum, in Japanese knotweed, (Polygonum cuspidatum), Polygonaceae

Picrocrocin
Picrocrocin, C16H26O7, monoterpene glucoside (Saffron-bitter), bitter taste, hay-like fragrance, an ester.
Picrocrocin is a beta-D-glucoside most responsible for the bitter taste of saffron.
See diagram, Picrocrocin

Piezoelectric
Ammonium dihydrogen phosphate, monobasic ammonium phosphate (piezoelectric crystal in microphones and transducers)
Earphones, crystal microphones: 38.2.05
Potassium sodium tartrate-4-water
Piezoelectricity (voltage produced by mechanical stress to crystals): 32.1.2.1
Piezoelectricity with red lead and sulfur: 35.33.0
Transducer, carbon microphone: 26.9.01

Pimpinellin
Pimpinellin, C13H10O5, chromen-2-one, furanocoumarin, tuberculostatic
It occurs in Pimpinella saxifraga roots, in Heracleum species, in Angelica, in Cyperus, in Artemisia.

Pinocembrin
Pinocembrin, C15H12O4, dihydrochrysin, dihydroxyflavanone, antioxidant, antineoplastic, vasodilator, neuroprotective
It occurs in human gut microbiota, in Piper sarmentosum.

Piperonal
Piperonal, C8H6O3, piperonyl aldehyde, heliotropine, (3,4-Methylenedioxybenzaldehyde), arenecarbaldehyde, benzodioxole, colourless lustrous crystals, irritant, fragrance, insect repellent, flavouring agent
It occurs in cherry, and in highbush blueberry Vaccinium corymbosum.

Pipettes
Pipettes, Handling and transferring chemicals: 3.4.10 (Safety)
Pipettes, Danger of using pipettes in the laboratory: 1.25 (Safety)
Pipettes, Microbiology: 4.4.2 (Safety)

Pitch
Pitch, (Chemistry), resinous semi-liquid distillate from wood tar, for caulking wooden ships, link torches were used in dark streets.

Plantamajoside
Plantamajoside, C29H36O16, phenylpropanoid, hydroxycinnamic acid, anti-inflammatory, anti-asthmatic, against plant pathogenic bacteria.
It occurs in Plantago, in Rehmania glutinosa.

Planteose,
Planteose, C18H32O16, (6F-alpha-D-Galactosylsucrose), trisaccharide
It occurs in Sesamum indicum.

Plaster of Paris
Plaster of Paris, calcium sulfate hemihydrate, hygroscopic, CaSO4.H2O, Harmful, very hot when water added to dry sulfate.
Plaster of Paris, calcium sulfate, gypsum: 35.22.6, (Geology)
Heat calcium sulfate, gypsum: 8.3.5
Fibrous plaster board with plaster of Paris: 3.2.6
Make objects and moulds with plaster of Paris: 3.2.7
Prepare fibrous plaster board with plaster of Paris: 3.2.6
Tests for strength of plaster of Paris bricks: 34.67.0

Plastics
Plastics recycling code: 3.4.0
PET, Birefringent clear plastics: 28.189, (Experiments)
Perlon plastic, Nylon polyamide: 3.7.6.1
Polymers and plastics
Plastics, Polymers and plastics: 3.0
Polymers and plastics
Tests for plastics, Burning tests for fabrics: 4.0.0

Pleuran
Pleuran, Β–Glucans, insoluble polysaccharide, C6H10O5)x, C18H32O16, anti-tumour drug.
It occurs in cell walls of oyster mushroom, Pleurotus ostreatus, white-rot fungus Phanerochaete chrysosporium and oats Avena sativa.

Plutonium, Pu
See Plutonium, Table of the Elements
See Plutonium, RSC
Plutonium, Pu, (Greek Ploutōn underworld god), alloyed with Gallium in nuclear weapons core, "the most complex element in the periodic table", isolated from uranium by Glen Seaborg in Chicago, 1942 in the Manhattan Project, later used in the first atomic bomb.

PMMA
PMMA, para-Methoxymethamphetamine, dangerous stimulant drug, "Dr Death"

Polonium, Po
See Polonium, Table of the Elements
See Polonium, RSC
(Latin,Polonia Poland, native country of Marie Curie), radioactive poison used to treat lung cancer

Poncirin
Poncirin, C28H34O14, flavanone glycoside, monomethoxyflavanone, disaccharide derivative, neohesperidoside.
It occurs in Poncirus trifoliata fruit, and in Rock thyme (Acinos alpinus).

Praseodymium, Pr
See Praseodymium, Table of the Elements
See Praseodymium, RSC
Praseodymium, Pr (Greek prasios green, didumos twin, didymium mineral), green compounds, used in ceramics, glass

Precipitates, Precipitation
Precipitates,substances deposited as a solid from a solution
Precipitation,as above, and rainfall
Precipitation reactions: 12.2.7
Coloured precipitates, double decomposition reactions: 12.2.4.02
Moisture leaves the air, precipitation: 37.8.0, (Weather)
Precipitates with ammonium carbonate: 12.12.4
Precipitates with sodium bicarbonate: 12.1.19
Precipitates with sodium carbonate: 12.1.26
Precipitation, decanting, filtration: 10.11.01
Precipitation reactions (double decomposition, double exchange, metathesis)
Precipitation, Moisture leaves the air: 37.8.0, (Weather)
Silver chloride precipitate in photography: 7.8.7.1
Suspensions and precipitates: 7.6.0, (Experiments)
Particles, Suspensions and precipitates

Prednisolone
Prednisolone, C21H28O5, metacortandralone, hydroretrocortine, predonine, corticosteroid, synthetic glucocorticosteroid, irritant, health hazard, anti-inflammatory, immunomodulating, decreases the number of circulating lymphocytes, induces cell differentiation, stimulates apoptosis in tumour cells, environmental hazard, a corticosteroid hormone receptor agonist, adrenergic, anti-inflammatory, antineoplastic, immunosuppressive, environmental contaminant, xenobiotic.

Prenylnaringenin
Prenylnaringenin, C20H20O5, 8-PN, flavaprenin, dimethylallylnaringenin, hopein, sophoraflavanone B, "minor flavonoid", prenylflavonoid, phytoestrogen, similar effects to estradiol, antifungal.
It occurs in hops (Humulus lupulus) resin, in beer, in Wyethia species.
It is produced from isoxanthohumol in fungal cells culture.

Proactinium, Pa
See Proactinium, Table of the Elements
See Protactinium, RSC
Pa, 91Pa, (proactinium "parent of actinium", because radioactive decay to Actinium), radioactive, toxic, no uses, most stable isotope is Protactinium-231.

Producer gas
Producer gas, air gas, similar to water gas, formed by passing air and steam over hot carbon

Progoitrin
Progoitrin, C11H19NO10S2, glucorapiferin, (2-hydroxy-3-butenyl glucosinolate), occurs in:
Cabbage (Brassica oleracea var. capitata), Brassicaceae,
Peanut, (Arachis hypogaea), Fabaceae
in Horseradish, (Armoracia rusticana), Brassicaceae
After digestion, it is processed to goitrin which decreases production of thyroid hormone, flavour component + breakdown hydrolysis products.
It occurs in rapeseed, in brown mustard, in cabbage, in Crambe abyssinica, precursor of goitrin causing bitter taste in Brassica vegetables and epigoitrin which affects thyroxin secretion.
Phenethyl glucosinolate potassium salt, C15H20NO9S2K, occurs in Brassica, in red cabbage, in Brussel sprouts, in savoy cabbage.
Progoitrin after ingestion may be converted to goitrin, C5H7NOS, which decreases thyroid hormone production.

Promethazine
Promethazine, C17H20N2S, phenothiazine derivative drug, sedative, antiallergic
See diagram,14.05
It is used to treat motion sickness, allergic reactions, nausea, and vomiting.

Promethium, Pm
See Promethium, Table of the Elements
See Promethium, RSC
Promethium, Pm (Greek Prometheus, who stole fire from the gods), synthesized in radiation laboratory

Propanethiol
Propanethiol, C3H8S, CH3(CH2)2SH, propane-1-thiol, n-propylthiol, propyl mercaptan,
Propanethiol is an alkanethiol, colourless to pale yellow liquid, offensive smell like cabbage, moderately toxic, less dense than water, slightly soluble in water, flammable, irritant.
It is used as insecticide, feedstock and herbicide, toxic fumes in a fire.
It occurs in onion Allium cepa and other Allium species, cooked chicken, beef, beer, American potato chips, and in durian Durio zibethinus.

Propionaldehyde
Propionaldehyde, C3H6O, CH3CH2CHO, propanal, propyl aldehyde, toxic by all routes, less dense than water, clear colorless liquid.
Highly flammable, suffocating fruity-like odour, occurs in Escherichia coli.
Propionaldehyde, Solution <20%, Not hazardous, but should not be ingested.

Propionic acid
Propionic acid, CH3CH2COOH, propanoic acid, Corrosive by all routes, Highly irritant vapour, skin irritant
Propionic acid, Solution / mixture <10%, Not hazardous (stored grains preservative)
Propionates, Food preservation
19.3.6.10 Food

Proteins
Prenylation: adding hydrophobic molecule to a protein so as to attach it to cell membrane
Protein breakdown by micro-organisms: 4.3.7
Burn carbohydrates, fats and proteins: 9.1.1
Casein, thermoset plastics: 3.5.6
Milk proteins: 16.3.0
Proteins, Multiple reagent strips
Tests for proteins: 9.4.0

Protocatechuic acid
Protocatechuic acid (PCA), C2H6O4, dihydroxybenzoic acid, phenolic acid, antioxidant, anti-inflammatory, protects liver, apoptosis of human leukemia cells.
It occurs in green tea, Hibiscus sabdariffa roselle, Boswellia dalzielii stem bark, Diospyros melanoxylon leaves, Euterpe oleracea açaí palm oil, and onion skins.

Protonated
Protonated is an organic chemistry term for when H+ ion is bonded to something.

Prunetin
Prunetin, Prunusetin, C16H12O5, flavone, hydroxyisoflavone, dehydrogenase inhibitor, anti-inflammatory
It occurs in Prunus species, in liquorice Glycyrrhiza glabra.

Psicose
Psicose, D-Psicose, D-allulose, C6H12O6, rare monosaccharide sugar
It occurs in wheat and Polytrichum commune.

Puerarin
Puerarin, C21H20O9, isoflavone, occurs in Bupleurum chinense and Pueraria calycina.
It has been used to treat alcohol withdrawal anxiety symptoms during treatment of alcohol abuse.

Purine
See diagram 16.21.10, Purines.
Two of the bases in nucleic acids, adenine and guanine, are purines.

Pyrrole
Pyrrole, C4H5N, (CH)4NH, imidole, aromatic, organic compound, colourless, volatile liquid, darkens on exposure to air.

Paludolactone
Paludolactone, sesquiterpene lactone, eudesmanolide lactone
It occurs in creeping ox-eye Wedelia paludosa.

Parthenolide
Parthenolide, C15H20O3, sesquiterpenoid lactone, germacranolide, insoluble, non-steroidal anti-inflammatory, antipyretic, febrifuge, release of | Serotonin | from blood platelets, used to treat migraine headaches, possibly anticancer
It occurs in flowers, fruit, leaves of | Feverfew, (Tanacetum parthenium) | Laurel-leaved magnolia |.

Patachoulol
Patachoulol, Patchouli alcohol, Patchouli camphor, C15H26O, tricyclic sesquiterpenoid tertiary alcohol, carbotricyclic compound
It occurs in essential oil Patchouli, (Pogostemon patchouli)
It is used to scent cosmetics.

Peppermint oil
Peppermint oil, terpene, Mentha piperita oil, C62H108O7 It occurs in the essential oil extracted from the leaves of Mentha x piperita.
It is used for aromatic properties, flavouring, treat disorders of digestive and respiratory system, pain relief.
Peppermint, (Mentha x piperita), Lamiaceae

Peridinin
Peridinin, C39H50O7, carotenoid pigment, light sensitive, associated with chlorophyll

Perilla ketone
Perilla ketone, C10H14O2, lung toxin affecting cattle and horses
It occurs in Perilla, (Perilla frutescens), Lamiaceae

Perillaldehyde
Perillaldehyde, C10H14O, sushi flavour, terpene aroma, perilla sugar
It occurs in Perilla, (Perilla frutescens), Lamiaceae

Perillartine
Perillartine, C10H15NO, perillartin, perilla sugar, X 2000 as sweet as sucrose
It is used in chewing gum,
It occurs in Perilla, (Perilla frutescens), Lamiaceae

Perillene
Perillene C10H14O, may be anti-inflammatory
It occurs in Perilla, (Perilla frutescens), Lamiaceae

Perillyl alcohol
Perillyl alcohol, monoterpene alcohol, woody odour, may be anticancer
It occurs in essential oils of lavender, bergamot, caraway, citrus oils, mints.

Petasin
Petasin, C20H28O3, sesquiterpene, ester of petasol (sencathenone), C15H22O2, and angelic acid, C5H8O2, in Butterbur, (Petasites hybridus), Asteraceae, may be anti-inflammatory

Phellandrene
Phellandrene, alpha-Phellandrene, Menthadiene, C10H16, monocyclic monoterpene, fragrance and flavouring agent with peppermint / citrus taste, in allspice
Cyclic monoterpene double bond isomers, having a similar molecular structure and similar chemical properties, are used in fragrances:
* alpha-Phellandrene, α-phellandrene in Eucalyptus radiata
* beta-phellandrene, β-phellandrene in oil of Canada balsam | Fennel, (Foeniculum vulgare) |Perilla, (Perilla frutescens), Lamiaceae
See diagram: Phellandrene

Phytoene
Phytoene, C40H64, carotene, carotenoid precursor, colourless, in most fruit and vegetables, tomato, carrot, oranges, absorb light in the UV range, may protect human skin, antioxidant, anti-inflammatory
(Phytoene/phytofluene are the first step in synthesis of all carotenoids in plants: phytoene --> neurosporene --> lycopene)

Phytofluene
Phytofluene, C40H62, carotene, carotenoid precursor, colourless, in most fruit and vegetables, orange colour of tomato, carrot, oranges, absorb light in the UV range, may protect human skin, antioxidant, anti-inflammatory (phytoene --> phytofluene)

Picrotoxins
Picrotoxins, C30H34O13, sesquiterpene lactone

Pinene
Pinene, C10H16, bicyclic monoterpene, alkene, pine needles aroma, in Canarium species, Burseraceae
Pinene is the terpene in natural turpentine from conifers and in essential oil of Rosemary
α-Pinene, C10H16, clear colourless liquid, turpentine odour, less dense than water, insoluble in water, vapours heavier than air, used as solvent It occurs in | Savory, (Satureja repandra) | Pinus | main component of Gum turpentine
A terpenoid, called a crystalline hydrate, C6H10(CH3)3(OH)2), is formed from acidification of α-Pinene
β-Pinene, C10H16, in pine forests, in Pinus | Cumin, (Cuminum cyminum) | Hops, (Humulus lupulus) | Cannabis, (Cannabis sativa) | Horsewood, (Clausena anisata), Rutaceae
Enantiomer alpha-pinene is more common in European pines, but enantiomer beta-pinene is more common in North America pines

Pinocamphone
Pinocamphone, C10H16O, monoterpene ketone, dark yellow liquid, aromatic, pleasant odour, in the alcoholic drink absinthe
Drinking absinthe may lead to disorders of the nervous system
It occurs in Hyssop, (Hyssopus officinalis), Lamiaceae

Piperitone
Piperitone, C10H16O, monoterpene ketone, cyclic terpene ketone, irritant, volatile oil component
D-piperitone occurs in Mint, (Mentha species), L-piperitone in Picea sitchensis

Prenol
Prenol, C5H10O, 3-Methyl-2-buten-1-ol, has a fruit-like odour, and occurs in citrus, tomato, passionfruit

Prilled
Prilled, pelletized, for machine-handled agricultural chemicals, e.g. prilled urea

Pulegone
Pulegone, C10H16O, monoterpene, natural pesticide, irritant, spearmint, fragrance and flavour ingredient, volatile oil component, mint taste biomarker
It occurs in Schizonepeta tenuifalia, Nepita species, Mentha species, Hedeoma pulegioides, cornmint, orange mint, peppermint, and blackcurrant.
It is in essential oil of catnip, Nepeta cataria

Prepare putty
Prepare putty (glazier's putty, painter's putty), with calcium carbonate paste (whiting), + linseed oil (+ white lead).
Putty is used as a, filler in glazing, to seal glass into frames.

Pyrazine
Pyrazine, C4H4N2, N2(C4H4), (1,4-diazine), heterocyclic aromatic organic compound
It occurs in Nicotiana tabacum, Coffea arabica, and Daphnia magna
The nutty tastes of roasted coconut is caused by pyrazines.