Chemistry topics starting with X, Y. and Z

School Science Lessons
2025-08-28

Chemistry, X, Y, Z
Chemistry, X
Chemistry, Y
Chemistry, Z

Chemistry, X
Contents
>Phenolic compounds, by name
X-rays, (Experiments)
Xanthoxylin
Xanthan gum, E415, (from corn sugar fermentation), (vegetable gum) Xanthene dyes
Xanthodrol
Xanthone
Xanthophylls, description
Xanthophylls, examples
Xanthoproteic test, Tests for proteins
Xanthotoxin
Xenon, Xe
Xylene, C8H10, Xylol, (Experiments)
Xylenols
Xylose

Chemistry, Y
Contents
Yangambin
Yangonin
Yeasts, (Experiments)
Yellow snowstorm reaction
Yoghurt
Yohimbine, alkaloid
Ytterbium, Yb
Yttrium, Y
Yuanhuacine
Yunaconitine, alkaloid

Chemistry, Z
Contents
Zeaxanthin
Zenker's solution, Prepare
Zeolite, (Geology)
Soil conditioner, Zeolites, (McLeod's Agriculture), Commercial.
Zephiran, Benzalkonium chloride
Ziehl-Neelsen stain, Prepare
Zinc, Zn
Zineb
Zingerone, Gingerol
Zingiberine
Ziploc, Sous vide cooking with a Ziploc bag
Zircon, ZrSiO4
Zirconium, Zr
Zirconium nitrate, Zr(NO3)4
Zirconia, ZrO2
Zizyphine, alkaloid
Zylon PBO fibre
Zylonite, Cellulose acetate
Zymase
Zymase, Tests for zymase and catalase in yeast
Zytel, Polyamides

Xanthodrol
Xanthodrol, C13H10O2, (9-hydroxyxanthene), (9-xanthenol), urea tests, Toxic, flammable

Xanthoxylin, C10H12O4
Xanthoxylin, carboxylic ester, crystalline phenolic ketone, 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
Xenon Table of Elements
Xenon, RSC
Atomic number: 54, Relative atomic mass: 131.29, RD 3.52(165 K), MP = -112 oC , BP = -108 oC ,
Specific heat capacity: 159 J kg-1 K-1
Commercial: Xenon Elements, Compounds
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, may not exist!
Specific heat capacity: 159 J kg-1 K-1.
Xenon occurs in lasers, fluorescent lamps.

Xylene, xylol, C8H10
Xylene [mixed isomers] is a colourless, sweet-smelling aromatic odour liquid that catches on fire easily, and floats on water.
It occurs naturally in petroleum and coal tar, and is produced from petroleum, and is toxic by ingestion.
Xylene is used as a solvent and in the printing, rubber, and leather industries..
It is also used as a cleaning agent, a thinner for paint, and in paints and varnishes, and in small amounts in airplane fuel and gasoline..
Xylenes are released into the atmosphere as fugitive emissions from industrial sources, from auto exhaust, and through volatilization from their use as solvents..
Inhalation exposure causes irritation of the eyes, nose, and throat, gastrointestinal effects, eye irritation, and central nervous system (CNS) effects..
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.
Prepare carbol xylol solution: 3.7
Prepare DPX mountant: 6.2
Prepare xylene and methylbenzoate solution: 3.28
Clean microscope slides and coverslips: 2.5.1
Cleaning agents, solvents: 2.3.7, (See: 5.)

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
Xylenol blue, C23H22O5S, p-Xylenolsulfonphthalein

Yangambin
Yangambin, C24H30O8, yangabin, furofuran lignan, peripheral vasodilation, antiallergic, anti-inflammatory.
It occurs in Rollinia species, Magnolia biondii, Virola elongata bark, Artemisia absinthium roots, Laurelia novae-zelandiae, and Tinospora sinensis
It is used as hallucinogenic snuff, arrow poison.

Yangonin
Yangonin, C15H14O4, (2-pyrone), aromatic ether, irritant, possible liver damage from use of kava in food.
It occurs in in kava, Piper methysticum root and Ranunculus silerifolius.
Kava, (Piper methysticum), kava kava

Ytterbium, Yb
Ytterbium, Table of the Elements
Ytterbium, RSC
Ytterbium, Yb, (Ytterby, Sweden), lanthanide, soft, silvery, malleable, in lasers
Ytterbium oxide, Yb2O3 in alloys, catalysts
Ytterbium (III) chloride hexahydrate, YbCl3.6H2O, animal food tracker

Yttrium, Y
Yttrium, Table of the Elements
Yttrium, RSC
Yttrium, Y, (Ytterby, Sweden), grey transition metal, protective oxide, red phosphorescence
Yttrium-90, reactor-produced medical radioisotope, half-life 64 hours, is used to treat liver cancer.
Yttrium, elements Y with Eu and Tb in TV screens (future shortfall), is used in microwave ferrites.
Yttrium (III) oxide, Y2O3, is used to make "1-2-3", super conductor, YBa2Cu3O7.

Zinc, Zn
Zinc Table of Elements
Zinc, RSC
Zinc, Zn (German zink zinc), 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 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 | the surface layer of zinc on galvanized iron sheets.
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 eating too many 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 = 420 oC , BP = 907 oC .
Specific heat capacity: 385 J kg-1 K-1.

Zinc: 35.2.73, (Geology)
Zinc chloride battery: 33.4.53.1, (many zince batteries below on this page)
Leclanché cell: 33.4.53.0, electric torch battery, flashlight battery
Zinc blende: 35.2.64, (Geology)
Zincite: 35.2.74, (Geology)
Zinc compounds
Zinc deficiency in soils: 6.13.9, (Agriculture)
Zinc residues: 3.3.7, (disposal)
Zinc toxicity: 4.16, (Safety)

Zinc experiments
Dilute hydrochloric acid with zinc: 17.1.6, (count bubbles)
Heat of displacement reaction: 14.1.6
Heat zinc with copper (II) oxide: 12.13.11
Heat zinc with sulfur: 12.2.10.7, Synthesis reactions
Iron and zinc with copper (II) sulfate solution: 12.14.12
Magnesium, or zinc, with copper (II) sulfate solution: 12.14.10
Prepare hydrogen gas: 13.3.15, zinc with dilute hydrochloric acid
Prepare zinc sulfate crystals: 12.10.8
Test a simple cell with different metals: 33.1.3.12, (zinc strip)
Test a simple electric cell with copper and zinc in dilute sulfuric acid: 33.1.7.10, (piece of zinc)
Tests for zinc: 12.11.3.30
Reactions of metals as reducing agents, Zinc experiments: 12.14.13a
Zinc plating of copper: 15.1.6, (zinc chloride)

Zinc compounds
Copper-zinc alloys, brass: 5.1.10
Smithsonite: 35.2.63, (ZnCO3), (Geology)
Sphalerite: 25.2.64, (ZnS), (Geology)
Zinc acetate dihydrate, C4H6O4Zn·2H2O or C4H10O6Zn, zinc ethanoate ZnC4H6O4, harmful if ingested, white granules, slightly efflorescent, faint vinegar odour.
Zinc bloom, hydrozincite, marionite, Zn5(CO3)2(OH)6, Zn[(OH)3(CO3)]2.5H2O, weathering production zinc deposit
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 800 oC
Zinc fluoride, ZnF2, ZnF2.4H2O, colourless crystals, needles, white crystalline mass, melting point of 872 oC
Zinc gluconate, C12H22O14Zn, in medicine for common cold
Zinc nitrate, Zn(NO3)2
Zinc oxide, ZnO
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 sulfate, ZnSO4
Zinc sulfide, ZnS
Zinc sulfite, ZnSO3, zinc sulfite dihydrate
Zincate, Zn(OH)42
Zincite, Geology)
Zineb, C4H6N2S4Zn, fungicide: 4.3.10

Zinc carbonate, ZnCO3
Zinc carbonate, colourless crystals or white crystalline powder, odourless, harmful, evolves carbon dioxide at 300 oC
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, melts at 275 oC
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
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 1975 oC
Zinc oxide with ammonium nitrate and some water may explode
Zinc oxide, ZnO, white to yellow, amorphous powder, RD 5.47, MP above 1 800 oC , white pigment, zincite, white zinc, zinc white
Chinese white, spartalite, craft, zinc sun cream medicine and other skin problems

Zinc sulfate, ZnSO4
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 50 oC , efflorescent in dry air, anhydrous at 200 oC , decomposes above 500 oC ,
white vitriol, zinc vitriol, white copperas, gosla rite, in zinc deficiency medicines
Prepare zinc sulfate crystals: 12.10.8
Sodium hydroxide with zinc sulfate solution: 12.1.10
Tests for oxidizing agents by change in colour of zinc with copper (II) sulfate: 15.4.17, (See: 3.)

Zinc sulfide, ZnS
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
Zinc sulfide with acids forms hydrogen sulfide gas

Zirconium, Zr
Zirconium Table of the Elements
Zirconium, RSC
Zirconium, Zr, is a grey amorphous powder, which may ignite spontaneously by static electricity and explode with geat intensity, especially in water.
Zirconium, Zr, (German zirkon zircon, zirconium ore), grey-white solid, lustrous transition metal
SPADNS fluoride reagent solution, 500 mL, C16H9N2Na3O11S3, [(HO)2C10H3(SO3Na)2N=NC6H4SO3Na], indicator for zirconium
Zirconium is used to make corrosion-resistant alloys, pyrotechnics, alloys to resist corrosion, nuclear fuel rods, photography flash bulbs, e.g. "Magicube".
It is a nuclear reactor neutron absorber
An "iSlice Cutter" has an zirconium-oxide ceramic blade that never rusts!

Zircon, ZrSiO4
2. Zircon, ZrSiO4, zirconium silicate, zirconium (IV) silicate, zirconium (IV) silicon oxide, zircon sand
Zircon, jacinth, jargoons, matura diamonds, in ceramic glazes
Zircon, Separate solids, density differences: 3.27
Zirconium, pegmatite, ZrSiO4, silicate: 35.2.9, (Geology)
Zircon, green zircon, ZrSiO4, a silicate of zirconium, a rare mineral, which may also occur as crystals in pegmatite:

Zirconia, ZrO2
Zirconia, ZrO2, zirconium dioxide, zirconia, zircon (IV) oxide, zircon-favas, white crystalline oxide, occurs in Baddeleyite mineral.
Cubic zirconia (CZ), optically flawless, colourless, crystalline zirconium dioxide, synthetic jewellery, zirconia dental crowns, 8.5 Mohs hardness scale
Pink zirconia, diamond look-alike, zirconium dioxide, synthetic jewellery

Zirconium nitrate, Zr(NO3)4br> 3. Zirconium nitrate, Zr(NO3)4, Toxic if ingested, inhalation harmful, skin sensitization, explosion by shock or friction or ignition
Zirconium nitrate with acids forms nitrogen dioxide gas
Zirconium dioxide + nitric acid --> Zirconium nitrate pentahydrate Zr(NO3)4·5H2O Other zirconium compounds
Zirconate, lead-zirconate-titanate (PZT), Piezoelectricity: 32.1.2.1
Zirconium tungstate, ZrW2O8, and Zirconium vanadate, ZrV2O7, negative thermal expansion

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+.

Phenolic compounds, by name
Anethole
Arbutin
Bergenin
Caffeic acid
Capsaicin
Carvacrol
Catechol
Chlorogenic acid
Cichoric acid
Cinnamaldehyde
Cinnamic acid
Coumarin
Cresol
Curcumin
Cyanidin
Emodin
Ethylphenol
Estradiol (oestradiol), C18H24O2
Estragole
Eugenol
Ferulic acid
Furanocoumarins
Gallic acid
Genistein, C15H10O5, occurs in soy, alfalfa, red clover, chickpeas, peanuts
Guaiacol, Methyoxyphenol
Juglone
Mangiferin
Methyl salicylate
Myristicin
Nordihydroguaiaretic acid
O-leuropein
Paeonol
Piceatannol
Plumbagin
Quercetin
Raspberry ketone
Resorcinol
Resveratrol Rosmarinic Acid
Salicyclic acid
Sesamol
Shikonin
Shogoal
Silibinin
Sinapinic acid
Tannic acid
Thymol
Tyrosine
Tyrosol
Umbelliferone
Urushiol
Vanillin
Zingerone