School Science Lessons
2024-06-17
Chemistry, X, Y, Z
Chemistry, X
Chemistry, Y
Chemistry, Z
Chemistry, X
Contents
X-rays
Xanthoxylin
Xanthan gum, Sols, (See: 5.)
Xanthene dyes
Xanthodrol
Xanthone
Xanthophylls
Xanthoproteic test, Tests for proteins
Xanthotoxin
Xenon, Xe
Xylene, C8H10, xylol
Xylenol
Xylol, C8H10, xylene
Xylose
Chemistry, Y
Contents
Yangambin, lignan
Yangonin, aromatic ether
Yeasts, (Experiments)
Yellow snowstorm reaction, (Experiments)
Yoghurt, Prepare yoghurt, test milk quality, (Experiment)
Yohimbine, alkaloid
Ytterbium, Yb
Yttrium, Y
Yuanhuacine, diterpenoid
Yunaconitine, alkaloid
Chemistry, Z
Contents
Zeaxanthin, xanthophyll pigment
Zenker's solution Prepare
Zeolite, (Geology)
Zephiran
Ziehl-Neelsen stain, Prepare
Zinc, Zn
Zineb, fungicide
Zingerone, Gingerol
Zingiberine, sesquiterpene
Ziploc Sous vide cooking with a Ziploc bag
Zircon, ZrSiO4
Zirconium, Zr
Zirconia, ZrO2
Zizyphine, alkaloid
Zylon PBO fibre, PBO
Zylonite, Cellulose acetate
Zymase, Tests for zymase and catalase in yeast
Zymosan, a β-1,3-glucan, found on yeast
Zytel, Polyamides
Xanthodrol
Xanthodrol, C13H10O2, (9-hydroxyxanthene), (9-xanthenol), urea tests, Toxic, flammable
Xanthophylls
Carotenoids, Carotenes and Xanthophylls
Cells, human cheek cells, Elodea plant cells: 9.1.1
Chromatography of chlorophyll pigments: 10.2.1
Egg structure: 9.4
Separate by chromatography, green leaf pigments: 3.24
Xanthophylls are hydrocarbons + oxygen, and are usually yellow pigments.
Xanthophylls, contain oxygen, usually yellow pigments, in the leaves of most plants.
Xanthophylls are oxygenated carotenes, the yellow leaf pigments of leaves, synthesized within plastids without need for light for synthesis.
However, theyt do absorb some wavelengths not absorbed by chlorophyll, so appear in etiolated leaves and plants with chlorosis nutrient deficiency.
In the leaves of deciduous plants, green chlorophyll covers up the yellow from the carotenoid pigments, except during autumn.
(Latin decidere to fall off)
Xanthoxylin, C10H12O4
Xanthoxylin, carboxylic ester, crystalline phenolic ketone, (derived from a phloroglucinol), in fats and oils,
Use to treat stomach spasms, fungus infections and pain.
It affects melanin content in the body.
It occurs in Sapium sebiferum, (Chinese tallow tree), in Zanthoxylum piperitum, (Japanese pepper tree).
Xenon, Xe
Atomic number: 54, Relative atomic mass: 131.29, RD 3.52(165 K), MP = -112oC, BP = -108oC,
Specific heat capacity: 159 J kg-1 K-1
See: Xenon Table of Elements
See: Xenon, RSC
See: Xenon Elements, Compounds, (Commercial).
Xenon, Xe, (Greek xenos foreign, stranger), colourless, odourless, non-metal noble gas at room temperature and pressure, 0.00001% of the atmosphere.
Xenic acid, xenon trioxide solution
Specific heat capacity: 159 J kg-1 K-1.
Xenon occurs in lasers, fluorescent lamps.
Xylene, xylol, C6H3(CH3)2OH
Dimethylbenzene, Xylene, 1,3-Dimethylbenzene
Xylene, C6H3(CH3)2OH, dimethylbenzene, Toxic by all routes, highly flammable
Xylol, Toxic by all routes, highly flammable, Carbol xylol, biology solution: 1.4
Xylene and methylbenzoate, biology solution: 1.12
Xylene cleaning agents, solvents: 2.20.4
Xylene
Xylene, C8H10, C6H4(CH3)2, m-Xylene anhydrous, 1,3-dimethylbenzene, solvent, Toxic, flammable dimethylbenzenes,
(3 isomers not separated), (prepare polyesters, Terylene)
Xylene cyanol FF, C25H27N2NaO6S2, acid blue 147, cyanol FF, histology dye, Toxic if ingested
Xylenes, ACS reagent, 98.5% xylenes + ethylbenzene basis, Xylene isomer mixture, CAS Number 1330-20-7
Xylol isomers:
* m-Xylol, m-xylene (1,3-Dimethylbenzene), Metaxylene, C8H10
* o-Xylol, o-xylene (1,2-Dimethylbenzene), Orthoxylene, C8H10
* p-Xylol, p-xylene (1,4-Dimethylbenzene), Paraxylene, C8H10
Low cost: from hardware stores and paint stores, as xylenes, (mixed dimethylbenzene isomers)
Xylene, curing agent for epoxy resin adhesives, surface coating, paint thinner, irritant, solvent for some marker pens and Canada balsam.
Xylol, oil-immersion microscopy clearing agent, removes immersion oil from objective, prepares embedded specimens and mounts.
Xylenol
Xylenol, C8H10O, (CH3)2(C6H3OH, (2,6-xylenol), (2,6-dimethylphenol), (2-hydroxy-m-xylene), (solvent, disinfectant)
Xylenol orange, C31H32N2O13S, disodium salt, tests for metal ions, Toxic if ingested
Xylenols, (CH3)2C6H3OH
Xylenols are volatile colourless solids, oily liquids, derivatives of phenol.
Xylenol orange, C31H32N2O13S, (metal indicator), Toxic if ingested, tetrasodium salt used for an indicator for metal titrations
2,4-xylenol, C16H20O2
2,6-xylenol, 2,6-dimethylphenol (DMP), C8H10O
2,4-Dimethylphenol, 4-Hydroxy-m-xylene, (CH3)2C6H3OH), from coal tar
Yangambin, C24H30O8
Yangambin, yangabin, is a furofuran lignan, peripheral vasodilation, antiallergic, anti-inflammatory.
It occurs in Rollinia species, in Magnolia biondii, in Virola elongata bark, in Artemisia absinthium roots.
It is used as hallucinogenic snuff, arrow poison.
Yangonin, C15H14O4
Yangonin is a (2-pyrone), an aromatic ether, irritant, possible liver damage from use of kava in food.
It occurs in in kava, Piper methysticum root.
Ytterbium, Yb
Ytterbium, Yb, (Ytterby, Sweden), lanthanide, soft, silvery, malleable, in lasers
See: Ytterbium, Table of the Elements
See: Ytterbium, RSC
Ytterbium oxide, Yb2O3 in alloys, catalysts
Ytterbium (III) chloride hexahydrate, YbCl3.6H2O, animal food tracker
Yttrium, Y
Yttrium, Y, (Ytterby, Sweden), grey transition metal, protective oxide, red phosphorescence
See: Yttrium, Table of the Elements
See: Yttrium, RSC
Yttrium-90, reactor-produced medical radioisotope, half-life 64 hours, used to treat liver cancer
Yttrium, elements Y with Eu and Tb in TV screens (future shortfall), in microwave ferrites
Yttrium (III) oxide, Y2O3, used to make "1-2-3", super conductor, YBa2Cu3O7
Zinc, Zn
See: Zinc Table of Elements
Zinc Elements, Compounds, (Commercial).
Zinc
Zinc, Zn (German zink), hard, lustrous, blue-white metal that forms protective oxide layer in air preventing further oxidation.
Zinc is sold as zinc metal mossy, zinc dust (FLAM), zinc filings (FLAM), zinc powder (FLAM), zinc foil, zinc strip, AAS standard solution, granulated zinc.
Zince can be obtained from dry cell battery case, zinc blocks from electronics supply shops for anodes, building supplies shops sell zinc sheets for roof flashing.
Zinc dust is dangerous as a fine powder and the powder is not permitted in schools.
It is highly flammable, ignites on heating, forms explosive mixtures with S, Br2, I2, explosive if finely dispersed in air, Toxic if inhaled.
Zinc dust, that is flammable and has been used in the past to make rocket fuel by mixing it with finely-divided sulfur.
Zinc dust is highly flammable.
Zinc dust, ignites on heating, explosive mixtures with S, Br2, I2, explosive if finely dispersed in air, Toxic if inhaled.
Zinc / sulfur mixtures are extremely hazardous, liable to combust violently on ignition and release large amounts of sulfur dioxide from oxidation of unreacted sulfur.
Zinc dust forms hazardous mixtures with iodine and many oxidizing agents, e.g. manganese dioxide, potassium nitrate and potassium permanganate.
Use zinc powder, or granulated zinc, foil or low cost casing of unused zinc-carbon battery (99%+ zinc), for teaching about:
electrochemical cells,
reactivity of metals,
displacement reactions,
form hydrogen with dilute acids,
Daniell cell,
surface layer of galvanized iron sheets to prevent the iron from rusting.
Zinc is used as foil in a dry cell battery casings, alloys and brass, as a micro nutrient (trace element) as salts or compounds, not as the pure element.
Zinc anodes for electroplating industry, increase life of high carbon steel fishing hooks.
Zinc anode nuts to protect underground and submerged threads.
Time release anodes to release fishing pots.
Zinc string and zinc ribbon to protect double bottom tanks of ships, mooring chains, underground storage tanks and pipelines.
Zinc G-clamps and I-bolts to attach anode to structures.
Brass is an alloy of copper and zinc.
Hydrozincite, Zn[(OH)3CO3], zinc bloom
US cent coins minted in 1983, zinc + thin copper plating
Zinc is extracted from zinc blende (sphalerite, ZnS)
High level of zinc in the diet is undesirable, e.g. from oysters.
Zinc deficiency symptoms occur where people live on unleavened bread made from highly extracted wheat flour and no meat or yeast products in the diet.
Zinc is a cofactor for about 20 enzymes, e.g. alcohol dehydrogenase that breaks down ethanol and carboxypeptidase that catalyses the hydrolysis of proteins.
The recommended daily allowance, RDA, is 15 mg for males and 12 mg for females.
Atomic number: 30, Relative atomic mass: 65.39, RD 7.14, MP = 420oC, BP = 907oC.
Specific heat capacity: 385 J kg-1 K-1.
Zinc (Commercial)
Zinc, (Geology)
See: Zinc, Table of the Elements
See: Zinc, RSC
33.4.2 Zinc-carbon cell, Dry cell torch battery, (flashlight battery)
Zinc blende, (Geology)
Zincite, (Geology)
Zinc compounds
Zinc deficiency in soils: 6.13.9, (Agriculture)
Zinc, (Geology)
Zinc residues: 3.5.7, (disposal)
Zinc toxicity: 4.1.16, (Safety)
Tests for zinc: 12.11.3.30
Synthesis reactions (combination reactions, direct union of elements): 12.22.2.0
Zinc experiments
Dilute hydrochloric acid with zinc, (count bubbles): 17.1.6
Group 4 tests for Co2+, Mn2+, Ni2+, Zn2+: 12.11.4.4
Heat of displacement reaction: 14.1.6
Heat zinc with copper (II) oxide: 12.13.11
Heat zinc with sulfur: 12.2.10.7
Magnesium, or zinc, with copper (II) sulfate solution: 12.14.10
Prepare hydrogen gas: 3.41.2.0, (Zinc with hydrochloric acid)
Test a simple electric cell with copper and zinc in dilute sulfuric acid: 33.84.3
Zinc combustion: 12.14.11
Zinc combustion: 12.5.1
Zinc displaces lead from lead nitrate solution: 12.14.12
Zinc dust decolorizes bromine water
Zinc plating, electroplating, of copper: 15.1.6
Zinc powder with iodine solution: 12.14.17
Zinc with acids: 12.14.15
Zinc with alkalis: 12.14.16
Zinc with copper in sulfuric acid: 12.14.14
Zinc with lead nitrate solution: 12.14.13
Zinc with lead nitrate solution: 12.14.2.4
Zinc compounds
Copper-zinc alloys, brass: 5.1.10
Smithsonite, ZnCO3, (basic zinc carbonate, ZnCO3.2ZnO.3H2O): 35.20.40, (Geology)
Sphalerite, ZnS, zinc blende: 35.20.41, (Geology)
Zinc acetate dihydrate, C4H6O4Zn·2H2O or C4H10O6Zn, zinc ethanoate ZnC4H6O4, harmful if ingested, white granules, slightly efflorescent, faint vinegar odour.
Zinc benzoate, C14H10O4Zn
Zinc blende, ZnS
Zinc bloom, hydrozincite, marionite, Zn5(CO3)2(OH)6, Zn[(OH)3(CO3)]2.5H2O, weathering production zinc deposit
Zinc bromide, ZnBr2
Zinc carbonate, ZnCO3
Zinc (II) chloride
Zinc chromate, ZnCrO4
Zinc cyanide, Zn(CN)2, white powder, or colourless, rhombic crystals, bitter almonds odour, decomposes at 800oC
Zinc fluoride, ZnF2, ZnF2.4H2O, colourless crystals, needles, white crystalline mass, melting point of 872oC
Zinc gluconate, C12H22O14Zn, in medicine for common cold
Zinc hydroxide, Zn(OH)2, amphoteric
Zinc iodide, ZnI2, beige powder, Harmful, corrosive
Zinc nitrate, Zn(NO3)2
Zinc oxide, ZnO
Zinc perchlorate hexahydrate, Zn(ClO4)2.6H2O
Zinc phosphate, Zn3(PO4)2, primer, rust prevention
Zinc phosphide, Zn3P2, dark grey crystals, or lustrous or dull powder, faint phosphorus or garlic odour, rat bait
Zinc potassium chromate, KZn2.(OH)(CrO4)2, yellow powder, green-yellow, odourless, metal priming paint against corrosion
Zinc residues: 3.7
Zinc sulfate, ZnSO4
Zinc sulfide, ZnS
Zinc sulfite, ZnSO3, zinc sulfite dihydrate
Zincate, Zn(OH)42
Zincite, Geology)
Zineb, C4H6N2S4Zn, fungicide: 4.6.6
Zinc carbonate, ZnCO3
Smithsonite mineral: 35.20.40, (Geology)
Zinc carbonate, colourless crystals or white crystalline powder, odourless, harmful, evolves carbon dioxide at 300oC
Zinc carbonate, ZnCO3 (basic zinc carbonate, ZnCO3.2ZnO.3H2O
Zinc carbonate basic, ZnCO3.2ZnO.3H2O, smithsonite, calamine (calamine lotion for itches and rashes)
Zinc (II) chloride, ZnCl2
Zinc (II) chloride anhydrous, ZnCl2, Harmful if ingested, corrosive to skin, eyes
Zinc chloride, Solution / mixture < 5%, Not hazardous, hygroscopic white granules or crystals, fused pieces,
or rods, odourless, white fumes acrid odour, melts at 275oC
Zinc chloride with sodium hydroxide: 12.7.7.1
Zinc chloride (soln), 32% in HCl soldering flux, "killed acid", tinner's fluid, butter of zinc, Harmful
Zinc chloride, killed acid, Append E, Environment danger, Corrosive, (COR 2331), used to clean copper
Zinc chromate, ZnCrO4
Zinc chromate is used as a yellow rust-prevention primer on Fe and Al, but chromium toxicity against such use
Highly toxic if ingested or absorbed through skin, do not inhale yellow, fine powder or yellow prisms, odourless
Zinc chromate, Solution / mixture < 0.1%, Not hazardous
Zinc chromite, chromium zinc oxide, ZnO.xCr2O3
Zinc nitrate, Zn(NO3)2
Zinc nitrate hexahydrate, hydrated, Zn(NO3)2.6H2O, Harmful if ingested
Zinc nitrate, Explosive mixtures with combustibles and organic compounds, toxic fumes
Zinc oxide, ZnO
Dilute acids and basic oxides, zinc oxide : 12.3.5.1
Zinc oxide
Zinc oxide, ZnO, amphoteric (sunscreen cream)
Zinc oxide, flowers of zinc, philosopher's wool, spartalite, zincite, zinc white, Chinese white
Zinc oxide, white solid turns yellow on heating, melting point 1975oC
Zinc oxide with ammonium nitrate and some water may explode
Zinc oxide, ZnO, white to yellow, amorphous powder, RD 5.47, MP above 1 800oC, white pigment, zincite, white zinc, zinc white
Chinese white, spartalite, craft, zinc sun cream medicine and other skin problems
Zinc sulfate, ZnSO4
Prepare zinc sulfate crystals: 12.2.4.2
Tests for oxidizing agents by change in colour of zinc with copper (II) sulfate: 15.2.10
Zinc sulfate
Zinc sulfate, ZnSO4, zinc sulfate(VI)-7-water, zinc sulfate heptahydrate, ZnSO4.7H2O (electrochemical cells),
Harmful if ingested, sulfur dioxide formed when heated
Zinc sulfate, colourless rhombic crystals, transparent prisms or small needles, efflorescent in dry air
Zinc sulfate heptahydrate, ZnSO4.7H2O, For 0.1 M solution, 28.8 g in 1 L water
Zinc sulfate hydrated, goslarite, white vitriol, white copperas
Zinc sulfate monohydrate, ZnSO4.H2O, zinc sulfate heptahydrate, ZnSO4.7H2O, colourless, odourless, white rhombic crystals or powder,
RD 1.97, MP about 50oC, efflorescent in dry air, anhydrous at 200oC, decomposes above 500oC,
white vitriol, zinc vitriol, white copperas, gosla rite, in zinc deficiency medicines
Zinc sulfide, ZnS
Models, inorganic, Zinc sulfide, ZnS, (Commercial)
Zinc sulfide
Zinc sulfide, ZnS, white-yellow solid, soluble, sublimes, phosphor, pigment, Toxic if ingested, skin irritant
Zinc sulfide, ZnS, colourless hexagonal crystals, or white / grey-white powder or yellow powder, in sphalerite
Sphalerite, ZnS, zinc blende: 35.20.41, (Geology)
Zinc sulfide with acids forms hydrogen sulfide gas
Zirconium, Zr
Zirconium, Zr, (German zirkon zircon, zirconium ore), grey, lustrous transition metal
See: Zirconium Table of the Elements
See: Zirconium, RSC
Zirconium, properties
SPADNS fluoride reagent solution, 500 mL, C16H9N2Na3O11S3, [(HO)2C10H3(SO3Na)2N=NC6H4SO3Na], indicator for zirconium
Zirconium, properties
Zirconium, Zr (German zirkon zircon, zirconium ore), grey, lustrous transition metal
An "iSlice Cutter" has an zirconium-oxide ceramic blade that never rusts
Zirconium, alloys to resist corrosion, nuclear fuel rods, grey-white solid, transition element, in zircon ZrSiO4, zirconium wire used in
photography flash bulbs, camera flash cubes, e.g. "Magicube", nuclear reactor neutron absorber
Zircalloy, Zr + Sn, Fe, Cr
Zirconate (IV), ZrO3-
Zirconium (IV) oxynitrate hydrate, ZrO(NO3)2 xH2O
Zirconium acetate, C8H12O8Zr
Zirconium carbonate, Zr3CO8
Zirconium nitrate, Zr(NO3)4.5H2O, Toxic if ingested, inhalation harmful, skin sensitization, explosion by shock or friction or ignition
Zirconium nitrate, use small amounts
Zirconium nitrate with acids forms nitrogen dioxide gas
Zirconium oxychloride octahydrate, ZrOCl2 8H2O
Zirconate, lead-zirconate-titanate (PZT), Piezoelectricity: 32.1.2.1
Zirconium, pegmatite, ZrSiO4, silicate: 35.21.3, (Geology)
Zirconium (IV) oxide, ZrO2, zirconia, baddeleyite, for craft, fuel cell electrolyte
Zirconium tungstate, ZrW2O8, negative thermal expansion
Zirconium vanadate, ZrV2O7, negative thermal expansion
Zircon, ZrSiO4
Zircon is zirconium silicate, ZrSiO4
Zirconium (IV) silicate, Zirconium (IV) silicon oxide, ZrSiO4
Zircon, zirconium silicate, ZrSiO4, jacinth, jargoons, Matura diamonds, in ceramic glazes
Zircon, pegmatite, beryl, topaz, tourmaline: 35.21.3, (Geology)
Zircon sand
Zircon, Separate solids, density differences: 3.27
Zirconia, ZrO2
Zirconia, zirconium dioxide, zircon dioxide, ZrO2, zircon (IV) oxide, zircon-favas
Zirconia, substitute diamond, not "zircon"
Baddeleyite mineral contains zirconium oxide, zirconia, ZrO2
Cubic zirconia (CZ), optically flawless, colourless, crystalline zirconium dioxide, ZrO2, synthetic jewellery, 8.5 Mohs hardness scale
Pink zirconia, diamond look-alike, zirconium dioxide, ZrO2, synthetic jewellery
12.21.1 Reactions of zinc and zinc compounds
1. Hold a piece of zinc foil in the Bunsen burner flame, using tongs.
Note the zinc oxide forms that is yellow when hot and white when cold.
2. Add sodium carbonate solution to zinc sulfate solution.
Observe the white precipitate of basic zinc carbonate, ZnCO3.2Zn(OH)2H2O.
3. Add sodium hydrogen carbonate to zinc sulfate solution.
Note the white precipitate of the normal carbonate, ZnCO3.
4. Add drops of sodium hydroxide solution to zinc sulfate solution.
Observe the white precipitate of zinc hydroxide that dissolves in excess of sodium hydroxide solution to form sodium zincate.
Pass hydrogen sulfide is passed through the sodium zincate solution.
Note the white precipitate of zinc sulfide.
Zinc hydroxide is amphoteric.
ZnSO4 + 2NaOH --> Zn(OH)2 + Na2SO4
Zn(OH)2 + 2NaOH --> Na2ZnO2 + 2H2O
(Note: Na2ZnO2 is sodium zincate)
5. Add drops of ammonium sulfide solution to zinc sulfate solution.
Note the white precipitate of zinc sulfide that may be discoloured.
6. Dip a rolled filter paper into a concentrated solution of zinc sulfate with added cobalt nitrate solution.
Burn the filter paper on wire gauze and note the remaining green ash, Rinmann's green.
7. Add drops of ammonium hydroxide to zinc sulfate solution.
The precipitate of zinc hydroxide dissolves in excess, due to the formation of a complex ion, [Zn(NH3)2]2+.