School Science Experiments
2019-02-21
Please send comments to: J.Elfick@uq.edu.au

Chemistry D
Table of Contents
d-block element, transition element (transition metal), Sc to Hg
Dacron, Polyamides: 3.7.6
Daguerreotypes: 12.19.4.1
Dalapon, C3H4Cl2O2, herbicide: 16.7.2
Dalton's law of partial pressures: 20.0.8
Daminozide, C6H12N2O3, "Alar": 9.1.7.7 (Plant growthregulator)
See: Danger signs, (Commercial)
Daniell cell, porous pot, Zn anode, Cu cathode: 33.3.2 (Physics)
Dantron, C14H8O4, anthraquinone
Darmstadtium, Ds
Date rape drugs, Tranquillizers: 11.12.2
DCPIP (C12H7NCl2O2), 2, 6-dichlorophenolindophenol
DCMU, C9H10Cl2N2O, diuron, herbicide: 16.8.11
DDT (C6H4Cl)2CH-CCl3)
DEA list of chemicals: 3.9.5
Decalcifying solution: 4.18
Decanal, C10H20O, decyl aldehyde: 16.3.2.2
Decane (CnH2n+2), Alkanes, paraffins: 16.4.1.1
Decane, Tests for unsaturated alkanes: 16.4.1.6
Decanedioic acid, HOOC(CH2)8COOH, sebacic acid
Decanoic acid, CH3(CH2)8COOH, capric acid
Decanolactone: 16.1.5.7
Decanting: 10.11.02
Decarboxylation, removing carboxyl group from compound
deci, one tenth, e.g. decilitre = 1/10 litre
Decoctions (herbal decoctions): 5.04.3
Decomposition reactions
Decrepitation, Heat substances, sublimation, melting, decrepitation: 11.3.4
Decyl aldehyde, C10H20O, decanal
DEET. (C12H17NO)
Deficiency symptoms, minerals: 1.0.0 (Agriculture)
Degrees proof, proof spirit (alcohol concentration): 3.7.3
DEHP, C24H38O4, di-(2-ethylhexyl)phthalate, polyvinyl chloride resin plasticiser
De-icers, ice melts: 7.4.3.3
Deionized water, Distilled water: 6.3.1.3
Delafield's haematoxylin, Prepare, C16H14O6.xH2O, (microscopy stain): 3.13.1
Deliquescent substances
Delphinine, C33H45NO9
Demecolcine, C21H25NO5
Demineralized water, "demi water", minerals or salts removed, replaces expensive distilled water
Denature: Destroy structure of a protein by heating or oxidation.
Denature: The tertiary structure of a protein collapses, denatured, by heating, acid or agitation in air.
Denatured alcohol, methylated spirits
DendrobineC16H25NO2
Density: 11.0.0
Deoxylactucin, C15H16O4
Deoxyribose
Depression, Freezing point depression and boiling point elevation:24.1.04
Depression, Freezing point depression of carbonated water, cola: 24.1.05 (Experiment)
Deserpidine, C32H38N2O8
Desiccants, drying agents
See: Desiccators (Commercial)
Designer drugs: 11.11.13
Deslanoside, C47H74O19
DETE Managing Risks with Chemicals in DETE Workplaces
Detergents, SYNDET, Synthetic Detergents
See: Detergents (Commercial)
Dettol, Phenol, Carbolic acid: 16.1.0, (See 3.)
Deuterium, D, hydrogen isotope: 3.6.1
Devarda's alloy, AlCuZn
Dewar flask, vacuum flask, Heat transfer by: 22.2.8 (Physics)
Dexchlorpheniramine, Antihistamines: 11.11.5
Dextran, H(C6H10O5)xOH
Dextrins (C6H10O5)n
Dextrose, glucose (C6H12O6)
DHB, C21H24O6
Dhurrin, C14H17NO7
Diacetyl, CH3COCOCH3: 16.3.3.2
Diallyl disulfide, C6H10S2, Sulfides: 16.2.8.2
Dialysis: 9.181 Separate a colloid from a crystalloid by dialysis
See: Dialysis Tubing (Commercial)
Diamino compounds, e.g. Diaminoethane, C2H4(NH2)2
Diammonium, e.g. Diammonium hydrogen phosphate, (NH4)2HPO4
Diamond
Diastase, Tests for diastase activity: 9.3.10
Diatoms, Diatomaceous earth
Diazepam, C16H13ClN2O (Valium), Benzodiazepines: 16.3.4.0.5b
Diazines: See diagram 16.3.4.4
Diazo compounds, R2CN2: 16.3.4.0.5
Diazo prints, Blueprints and diazo prints: 2.3
Diazonium ion, C6H5N2+, forms unstable salts
Dibenzazepine, tricyclic anti-depressant, TCA
Dibenzoyl peroxide, C14H10O4, benzoyl peroxide, Toxic, Highly flammable, Not permitted in schools
Dibromo
Dibutyl phthalate, C16H22O4, DPB, plasticiser, food contaminant, colourless, oily liquid, weak odour
Dicarbides, C22-, acetylides: Calcium carbide, CaC2
Dicarboxylic acids (-dioic acid): 16.3.8.2
Dichlor, C3HCl2N3O3: 18.7.2.4
Dichloro-
Dichromate ion Cr2O72-
Dichromates
Dichromatism: 27.124
Dieldrin, C12H8Cl6O, "Cyclodiene"pesticides: 16.4.01
Dienes, diolefins: 16.1.1.2.2
Diesel fuel
Diethanolamine, C4H11NO2
Diethyl (-C2H5)2
Diethyl ether, C4H10O
Diethylamine, C4H11N
Diethylphenylenediamine, C10H16N2
Different measurements, billion, trillion: 6.2.0
Differentiation solution: 4.19
Diffusion, particles of matter: 10.1.0
See: Diffusion (Commercial)
Digitalose
Dihydroxyanthroquinone, C14H8O4, 1, 2-dihydroxyanthroquinone, alizarin, Toxic, aluminium ion indicator
Dihydroxyacetone, C3H6O3, Glycerone, Ketose sugars: 16.3.1.2b
Digitoxigenin, C23H34O4
Digitoxin, C41H64O13
Digoxin, C41H64O14
Diindolylmethane, C17H14N2
Dioscorine, C13H19O2
Dilatant compound, "Silly Putty", silicone: 7.2.6
Dilatant fluids, shear-thickening, stir-thickening, dilatant fluids, rheopectic fluids: 13.6.0.4
Dilead (II lead (IV) oxide, Lead (II/IV) oxide
Dill ether, C10H16O, anethofuran
Dillapiole, C12H14O4: 16.2.2.8
Dilute, Dilution
Dimer, molecule or compound formed from two identical molecules
Dimercury (I) chloride, Hg2Cl2, Calomel, mercury (I) chloride: 35.20.10.1
Dimethoate, C5H12NO3PS2, (insecticide): 16.4.2
Dimethoxyethane, CH3OCH2CH2OCH3, anhydrous 1, 2-dimethoxyethane, dimethylglycol, monoglyme
Dimethyl (CH3)2
Dimethylamine, C2H7N
Dimethyltryptamine, (DMT), C12H168N2
Dimorphism, Argonite (CaCO3)n: 35.33.2 (mineral)
Dinitrobromobenzene, C6H3BrN2O4, 2, 4-dinitrobromobenzene, 1-Bromo-2, 4-dinitrobenzene, yellow, Irritant
Dinitrogen monoxide, N2O, Nitrous oxide:: 13.1.27
Dinitrogen monoxide, N2O, Tests for dinitrogen oxide (nitrous oxide): 3.45.1
Dinitrogen tetroxide, Copper cycle reactions: 12.1.3
Dinitrogen tetroxide, Nitrogen dioxide, NO2: 13.1.23
Dinitrophenylhydrazine, DNPH, 2, 4-dinitrophenylhydrazine, 2, 4-DNPH, Explosive, Flammable, Harmful
Dinoseb, C10H12N2O5, fungicide and insecticide: 16.8.10
Dioctyl phthalate, C6H4(COOC8H17)2, DOP, plasticiser, acaricide
Dioscorine, C13H19O2
Diosmetin, C16H12O6
Dioxane, C4H8O2
Dioxane
Dioxins, "Agent orange", PCBs: 16.14.0
Dipentene, C10H16, racemic limonene
Dipentene, limonene, d-limonene, Toxic, steam distil orange peel then use cyclohexane to extract limonene
Diphenyl methanone, C13H10O, benzophenone, Harmful if ingested
Diphenylamine (C6H5)2NH, Toxic byall routes, impure samples may contain carcinogens
Diphosphane, P2H4
Dipotassium hydrogen phosphate (V), dipotassium hydrogen orthophosphate
Dipsticks to test the vitamin C, ascorbic acid, Content of food: 19.1.20 (Tests)
Direct union of elements
Disaccharides, C12H22O11: 16.3.1.4.0
Disappearing ink, invisible ink: 3.2.5.0
Discharge tubes, Gas discharge tubes: 38.8.1
See: Dishes, Petri dishes, weighing trays, (Commercial)
Dishwashing liquids, in Herbicides, weedicides: 16.8.13
Disinfectants, antiseptics and antibiotics: 9.215
Disodium hydrogen phosphate, Na2HPO4
Disodium tetraborate, Na2B4O7, borax
Disogenin, C27H42O3
Displacement reactions (substitution reactions)
Disposal of waste chemicals: 3.4.11, (Safety)
Disproportionation, Hydrogen peroxide with catalase: 17.3.1.3
Dissection kit: 1.30
Dissociation constant, Acid dissociation constant, Ka: 12.3.16
Dissociation, Strong acids and weak acids: 12.3.0.3
Dissolve
Dissolved oxygen in water, Winkler method: 18.3.2
Distil, distilled, distillation
See: Distilling flasks demineralized water, (Commercial)
Diterpenes, C20 (four isoprene units): 16.3.5.1.4
Diterpenoid alkaloids: 16.3.11
Diterpenoids, C20: 16.3.5.1.4a
Dithizone, C6H5NHNHCSN=NC6H5, dithiozone, diphenyl thiocarbazone, Toxic if ingested
Dithizone, spot tests for lead, copper, zinc complexes
Diuron, C9H10Cl2N2O, DCMU, herbicide: 16.8.11
dm3 = 1 litre
DMSO, [C2H6OS (CH3)2SO)], dimethyl sulfoxide: 16.2.8.9
DMT, Dimethyltryptamine, C12H168N2
DNA and RNA: 4.4.0
DNA, RNA, nucleosides, nucleic acids: 16.3.2.8
Docetaxel, C43H53NO14, taxotere
Dodecane, CH3(CH2)10CH3
Dodecanedioyl dichloride, ClCO(CH2)10COCl
Dodecanoic acid, CH3(CH2)10COOH, lauric acid
Dodecanol, CH3(CH2)11OH, lauryl alcohol
Dodecyl benzenesulfonic acid, C18H30O3S
Dolomite, CaMg(CO3)2: 35.19.1 (Geology)
Domestos solution, NaOCl: 9.2.26
DOP, C6H4(COOC8H17)2, dioctyl phthalate, plasticiser, acaricide
Dopa, L-Dopa, levodopa, C9H11NO4
Dopamine, C8H11NO2
Double decomposition, double replacement, double exchange reactions
Double salt
DPD test for swimming pools: 18.7.21.6
DPX mountant (for histology): 2.5
Drain cleaners, e.g. "Drano": 12.12.10
Drink can, beveragecan, aluminium can, beer can, soda pop can, "can"
Drinking straws, soda straws, "straws"
Drinking water test media: 18.7.1
See: Dropping Bottles, Droppers, (Commercial)
Drug abuse (tranquillizers): 11.11.0
Drugs, Toxic effect of drugs on water fleas: 16.7.29
Dry cell battery, Leclanché cells (Physics)
Dry cleaning spirit, White spirit (petroleum distillate)
Dry ice, Frozen carbon dioxide ("hot ice" "cardice"): 3.34.5
Drying agents, Desiccants
See: Drying Tubes (Commercial)
E. coli, Disulfide Oxidoreductase A
Dubnium, Db
Ductility and elongation of metal (ductile): 34.5.1.4
Duplicating fluid, methylated spirits
Dust explosions: 15.1.1 (Safety)
Dust masks (Safety)
Dusts, Sprays, white oils: 16.9.0, (Agriculture)
Duties of a teacher: 3.2.0
Dyes, pigments
Dynamite, Nitroglycerine: 16.1.3.0.3
Dysprosium, Dy

D-Glucose
D-Glucuronic acid
D-Glutamic acid
D-( -)-Fructose
D-(+)-Glucose
D-Tartaric acid
D-Xylose
D-Mannitol
D-Sorbitol
D-Serine
D-Tryptophan
D-Ribose.

Darmstadtium, Ds
Darmstadtium
, Ds (Darmstadt, Germany) where first produced, radioactive transuranic element.

DCPIP, Dichlorophenolindophenol, (C12H7NCl2O2)
DCPIP, 2, 6-dichlorophenolindophenol, dichloro-indophenol, dichlorophenol solution, tablets, Toxic
Dichlorophenolindophenol, 2, 4-D, herbicide: 16.7.6
Prepare DCIP solution: 3.8
Tests for vitamin C (L-ascorbic acid): 9.143
Toxicity, Poisons and First Aid: 3.10.0, (Table).

Decomposition reactions
12.2.3.0 Decomposition reactions
15.5.4 Electrolysis of water, decomposition of water, Hofmann voltameter, coulometer
12.11.3.4 Heat substances, sublimation, melting, decrepitation
8.4.0 Heat substances that decompose when heated, but may be reformed
3.30 Heat substances that decompose and lose mass when heated
3.22.0 Thermal decomposition.

3.22.0 Thermal decomposition
3.29 Collect and weigh the gaseous products of a burning candle
3.30.9 Decomposition of boric acid
3.30.1 Decomposition of carbonates
3.30.11 Decomposition of chlorates
3.30.15 Decomposition of chlorides
3.30.16 Decomposition of dichromates
3.30.12 Decomposition of ferricyanides
3.30.2 Decomposition of hydrogencarbonates
3.30.8 Decomposition of hydrates, hydrous salts
3.30.3 Decomposition of hydroxides
3.30.17 Decomposition of manganates
3.30.14 Decomposition of metals, metallic salts
3.30.4 Decomposition of nitrates
3.30.10 Decomposition of oxalicacid
3.30.5 Decomposition of oxides
3.30.13 Decomposition of phosphates
3.30.6 Decomposition of sulfates
3.30.7 Decomposition of sulfites
3.30 Heat substances that decompose and lose mass when heated
8.2.4 Thermal decomposition of acids.

12.19.4.1 Daguerreotypes
Daguerreotype is a direct positive image from silver amalgam particles forming on the surface of a highly polished sheet of silver after
exposure to light.
The process requires mercury vapour so should not be done in schools.
Daguerreotypes are made in three stages:
1. Expose a silver plate to iodine or bromine vapour to form a light-sensitive layer of silver halide.
When exposed to the light, photons dislodge the halides to leave silver.
So the halide remains on the plate only where the image is dark.
2. Expose the plate to mercury vapour so that the mercury forms silver-mercury crystals.
3. Wash the plate in sodium thiosulfate to remove the halogen fromthe plate leaving a silver surface that reflects back as black and
silver-mercury crystals that refract light as white.
Then the daguerreotypes were soon sealed in glass plates to protectthem from tarnishing of the silver.
Old daguerreotypes may be damaged by salts from sea air and spotlights..

DEET
DEET, C12H17NO, N, N-Diethyl-meta-toluamide, "PESTANAL" , short-term protection against Anopheles species mosquitoes rather
than Culicine mosquitoes.

Deliquescent substances
Be careful! Hygroscopic and deliquescent substances may absorb moisture from human tissue and so should be treated as
potentially highly corrosive!
Deliquescent substances are hygroscopic substances that absorb much water to form a concentrated solution of the substance.
Deliquescent chemicals absorb water from the air and dissolve in it to form a concentrated solution:
Citric acid CH8O7, (slight),
Cobalt (II) nitrate, Co(NO3)2.6H2O,
Magnesium chloride, MgCl2,
Potassium hydroxide, KOH,
Potassium iodate, KIO3, (slight),
Potassium iodide. KI, (slight),
Sodium nitrate (NaNO3), (if in moist air),
Sodium thiosulfate Na2S2O3.5H2O, (if in moist air).
Store deliquescent chemicals in an airtight container or in a desiccator.
When exposed to the air, sodium chloride neither gains nor loses water.
Pure sodium chloride NaCl, is not hygroscopic.
However, sodium chloride as table salt in a salt shaker may become sticky and hard to shake out because it contains deliquescent
magnesium chloride as an impurity.
Add calcium carbonate or dry rice grains to table salt to stop deliquescence.

Detergents, SYNDET, Synthetic Detergents
See: Detergents, (Commercial)
See: Models, Organic models, (Commercial)
Anionic detergents
Detergents in washing powders: 12.12.04
Detergent phosphates: 12.12.05
Detergents in place of soap solution: 12.13.8
Effect of detergents on freshwater organisms: 18.7.2
Laundry detergents: 12.12.07
Machine dishwashing detergents: 12.12.08
Prepare detergent, alcohol-based detergent:
12.13.9
Temporary emulsions and permanent emulsions: 7.8.3.3.

A detergent is a synthetic surfactant, not a soap, the sodium salts of natural fats.
A detergent has the cleansing properties of a soap but it does notcombine with any salts present as soap does in hard water.
So detergents holds dirt in suspension.
Use dish-washing detergent to clean coffee and tea stains, thermosbottles, walls, glass, porcelain, wooden furniture, and the outsides
of appliances, vases, bath dirt rings, prewash soaks of clothes (+bleach, + vinegar in rinse), white polyester, cooking utensils with
baked-on food.

Devarda's alloy
Reduces nitrate to ammonia: 12.11.2.2
Devardas alloy, AlCuZn, powder, 50% Cu, 45% Al, 5% Zn, tests for NO3-, reaction with NaOH strongly exothermic.

Dextran, H(C6H10O5)xOH
Dextran, α-1, 6-glucan with α-1, 3-branches
Dextran, H(C6H10O5)xOH, straight chain and branched polysaccharide, in dental plaque, reduce blood viscosity and thrombosis
Dextran, bacterium Leuconostoc mesenteroides + lactic acid bacteria convert sucrose to dextran, used to make sauerkraut.

Dextrins (C6H10O5)n
Dextrins, D-glucose polymers
Tests for dextrins in toast: 19.3.4.1
Prepare glucose with starch: 12.7.15.

Diamond
Carbon, Table of Elements
Allotropes, sulfur, carbon: 7.9.4.2
Breccia: 35.22.2 (Geology)
Chemical bonds: 3.01.0
Diamond: 35.41.2
Diamonds (Total internal reflection): 28.6.8, (Physics)
Glass knife (ceramic impregnated with diamond dust)
Hardness, Mohs' scale of hardness: 35.10, (See: 10. diamond)
Lustre (metallic and non-metallic lustre): 35.6
Measure refractive index: 4.125
Properties of non-metals: 7.3.2 (See 1.)

Dibromo
Bromocresol purple: 6.0
Bromophenol red
Bromothymol blue
16.14.1 PBDE, pentabromodiphenyl ether, C12H5Br5O
12.18.16 Ethylene dibromide, 1, 2-Dibromoethane
1, 4-Dibromobutane, C4H8Br2, Br(CH2)4Br,
tetramethylene dibromide, Irritant
12.18.17 Dibromomethane, methylene bromide
12.18.18 Dibromopropane.

Dichloro
Dichlor: 18.7.2.4
Dichlorobenzene, C6H4Cl2
Dichloroacetic acid, CHCl2COOH
Dichlorobiphenyl-4, 4'-diamine,
Dichlorodifluoromethane
, CCl2F2
Dichloroethane, ClC2H4Cl
Dichloromethane
, CH2Cl2
Dichlorophenolindophenol, DCPIP
DCIP, 2, 6-dichlorophenolindophenol
(2, 4-D) (2, 4-dichlorophenoxyacetic acid): 16.7.6 (Herbicide).

Dichloromethane, CH2Cl2, methylene chloride
Dichloromethane
15.2.7 Carcinogenic substances
24.3.7 Drinking bird heat engine, drinking duck, dippy bird, dunking bird
16.8.3 Extraction of caffeine andbenzoic acid from soft drinks, e.g. cola and lemonade
16.5.1.3 Methane with chlorine, (Dangerous experiment)
14.2.8 Methylene chloride, CH2Cl2, dichloromethane
19.6.1 Paints, safety advice forpaints and paint strippers (See: 7.)
3.4.7.3 Prepare nylon polymer (See: Experiment 3.)

DDT
DDT (C6H4Cl)2CH-CCl3, iinsecticide [Former name: dichlorodiphenyltrichloroethane
New IUPAC name: 1,1,1-trichloro-2,2-bis (4-chlorophenyl)ethane].
See diagram 16.3.4.0.6: DDT, methoxychlor, Synergists: piperonyl butoxide
Aromatic halogen compounds: 16.3.4.0.6
DDT (in agriculture): 16.3.1
Dioxins, Agent orange, PCBs: 16.14.0 (See 2.)
Pediculosis, lice, louse, infection, Phthirus pubis: 10.5.10.

Diamino compounds
Diamino compounds contain 2 amino groups or substituted amino groups.
Diaminoethane
Diaminoethane, 1, 2-Diaminoethane, NH2CH2CH2NH2, 1, 2 Ethanediamine, ethylenediamine, polyamine, allergen, colourless liquid,
ammonia smell, related to EDTA, chelate, fungicide, Toxic by all routes, corrosive
1, 2-Diaminoethane, Solution < 1%, Not hazardous.

EDTA, Ethylenediaminetetraacetic acid, edetic acid, [(HOOCCH2)2NCH2], C10H16N2O8: 9.10.0.

Diaminobiphenyl, C12H12N2, (C6H4NH2)2, 4, 4'-diaminobiphenyl, benzidine, Toxic by all routes, Not permitted in schools

Diaminohexane, 1, 6-diaminohexane, C6H16N2, H2N(CH2)6NH2, hexamethylenediamine, ethylenediamine (1, 6-hexanediamine),
HMDA, hexamine, methenamine, urotropine, store in refrigerator, strongly alkaline (use < 25 mL 5% solution in water)
1, 6-Diaminohexane is used to make nylon polymer, hexamine fuel tablets, (heat tablets, Esbit) (not approved, USA, Australia),
Flammable, irritant.
E239 Preservative food additive

Diammonium
Diammonium copper (II) sulfate (VI)-6-water, Cu(NH3)4SO4.H2O, ammonium cupric sulfate, fire extinguisher, Environment danger
Diammonium hydrogen phosphate (NH4)2HPO4, ammonium hydrogen phosphate dibasic, in fertilizers, Toxic
Diammonium thiosulfate (NH4)2S2O3, ammonium thiosulfate, photography rapid fixer, fertilizer, reducing agent, Environment danger.

Diatoms, Diatomaceous earth
Diatoms, Phylum Bacillariophyta: 1.0
Diatomaceous earth, absorbacide (Agriculture): 16.9.4
Filters (Swimming pools): 18.7.20
Nitroglycerine (UK), Nitroglycerin (USA): 16.1.3.0.3

Dichloroacetic acid
Dichloroacetic acid, dichloroethanoic acid, DCA, CHCl2COOH, Toxic by all routes, Vapour irritates lungs
Dichloroacetic acid, Solution < 1%, Not hazardous (in chlorinated drinking water)

Dichlorobenzene, C6H4Cl2
1, 4-Dichlorobenzene, C6H4Cl2
1, 2-dichlorobenzene, o-dichlorobenzene, Toxic, avoid inhalation ofvapour
1, 2-dichlorobenzene. Solution < 5% Not hazardous
1, 4-dichlorobenzene, Solution < 25%, Not hazardous
1, 4-dichlorobenzene, Melting point of 1, 4-dichlorobenzene, C6H4Cl2: 7.4.2.1
1, 4-dichlorobenzene, para-dichlorobenzene, p-DCB), strong odour, used in mothballs
Reaction of chlorine with benzene: 13.4.6

1, 4-Dichlorobenzene, C6H4Cl2, m.p. 53oC, crystalline, p-dichlorobenzene, p-DCB, para-dichlorobenzene, 1, 4-dichlorobenzol,
"dichlorobenzene", Toxic if ingested, colourless, strong odour, deodorant, (solid blocks deodorant in male toilets), pesticide,
replacement for naphthalene mothballs
Use ethanol to prepare dilute solutions.
Substitute hexadecan-1-ol or octadecan-1-ol for melting point curveexperiments.

Dichlorobiphenyl-4, 4'-diamine, 3, 3'-dichlorobenzidine, Toxic by all routes, Not permitted in schools
2, 2'-dichlorodiethyl ether, dichloroether, dichlorodiethyl ether, Toxic by all routes, Not permitted in schools

Dichlorodifluoromethane, CCl2F2, Freon 12, CFCs, chlorofluorocarbons, "Freons": 12.19.5.0

Dichloroethane, ClC2H4Cl, 1, 2-dichloroethane, ethylene dichloride, dichloroethylene, Freon 150, Toxic,
Highly flammable, clear, thick liquid that has a pleasant odour.
Used to make vinyl chloride, polystyrene, SBR latex and chlorinatedsolvents, e.g. trichloroethane, to remove grease, resins, glue and
dirt, "anti-knock" compound in leaded petrol

Dichloromethane, CH2Cl2, methylene chloride, methylene dichloride, Freon 30, Toxic by all routes, possibly carcinogenic
Dichloromethane, Solution < 1%, Not hazardous
Colourless liquid, b.p. 41oC (refrigerant, degreasing, cleaning fluid, paint strippers, solvent), ozone-depleting chemical souse very
small amounts,
Use ethanol as solvent for dilute solutions.
organic solvent, in paint strippers, low B.P. of 39.6oC

Dichromates, - Cr2O7-
Dichromates, strong oxidizing agent, e.g. potassium dichromate K2Cr2O7, usually orange-red salts
Chromates, dichromates, hazards: 3.7.4
Reactions of dichromates, potassium dichromate: 12.5.3
Lead chromate, orange-yellow powder, S.G. 6.3, insoluble in water, acetic acid, and ammonia, but soluble in acid and alkalis.
If heated to decomposition emits toxic fumes of lead.
Oxidize
compounds to chromates, CrO42-: 12.5.5
Potassium dichromate, K2Cr2O7
Potassium hexacyanochromate (III), C6CrK3N6
Reinecke salt, C4H10CrN7S4
Tris (acetonitrile) tricarbonylchromium (0), C9H9CrN3O3
Chromic acid, Ionization reactions: 12.5.7
Potassium chromate, soluble in cold and hot water, insoluble in alcohol.
Sodium dichromate, red-orange crystals, S.G. 2.35, soluble in water.
Sodium dichromate, insoluble in alcohol. If heated to decomposition, emits toxic fumes of sodium monoxide.
Strontium chromate, soluble in cold and hot water, hydrochloric acid, nitric acid, acetic acid, ammonium salts.
Tests for chromates: 12.11.5.9
Zinc chromate, insoluble in cold water and acetone, soluble in hotwater, liquid ammonia.

Diesel fuel
Adiabatic change, thermodynamics: 20.4.05
Ammonium nitrate, diesel / ammonium nitrate mixtures, Not permittedin schools
Diesel oil, gas oil or diesel distillate, diesel fuel, heating oil:16.1.12.5
Fuels, fuel cell
Separate by fractional distillation: 10.6.0

Diethyl (-C2H5)2
Diethyl ether, C4H10O
Diethyl ketone, pentan-3-one
Diethyl sulfate, Toxic by all routes, Not permitted in schools
Diethylamine, C4H11N
Diethylaminopropylene, EAPA, curing agent for epoxy resin adhesive, surface coating, irritant
Diethylene glycol, C4H10O3, DEG (cosmetics, photography developer), Toxic
Diethylenetriamine, C4H13N3 (NH2CH2CH2)2NH, DTA, tridentate ligand, curing agent for epoxy resin adhesive, surface coating,
Irritant

Diethylphenylenediamine, C10H16N2 (C2H5)2NC6H4NH2, [N1, N1diethylbenzene], Toxic by all routes
N, N-diethyl-p-phenylenediamine, Solution < 3%, Not hazardous

Diethyl ether, C4H10O
Diethyl ether, C4H10O (C2H5)2O, C2H5OC2H5, ethoxyethane, ethyl oxide, ethyl ether, sulfuric ether, anaesthetic "ether",
Toxic by all routes, Not permitted in schools
Commercial: Diethyl ether, ACS reagent, anhydrous, 99.0%, containsBHT as inhibitor
Diethyl ether forms dense vapour that flows along bench or floor topoint of ignition.
Diethyl ether, on standing forms diethyl peroxide, that is less volatile and remains an explosive residue.
Diethyl ether, Flammable: 7.9.22, (See 3.)

Dilution
Dilution equation: C1V1 = C2V2
Concentration (start) X Volume (start) = Concentration (final) X Volume (final)
Colour change of diluted potassium permanganate: 3.3.1
Dilute acids with alkalis: 5.3.0.1
Particles of matter and dilution: 3.56
Prepare dilute buffer solutions: 12.10.7.1
Prepare serial dilutions: 5.2.0
Reactions of dilute acids: 12.3.1

Dimethyl
Dimethyl-3-octanol, C10H22O, monoterpene.
Dimethyl aminoazobenzene-4-sulfonate, C12H11N3, 4-aminoazobenzene, aniline yellow, orange powder, salts used for azo dyes.
Dimethyl aniline, C8H11N (CH3)2C6H3NH2, 2, 4-dimethylaniline.
Dimethyl benzene (CH3)2C6H4, one of 3 isomers is Xylene, 1, 3-Dimethylbenzene.
Dimethyl disulfide, CH3SSCH3, DMDS, volatile, offensive garlic-like odour in bad breath, in municipal solid waste landfill.
Dimethyl formamide (CH3)2NCOH, DMF, [N, N, dimethylformamide], solvent, paint thinner, odourless, but fish smell if impure.
Dimethyl glyoxime, C4H8N2O2, (CH3C(NOH)C(NOH)CH3), DMG, Toxic if ingested, ligand, Tests for nickel: 12.11.3.24.
Dimethyl polysiloxane (C2H6OSi)n, polydimethylsiloxane, PDMS, food additive E900.
Dimethyl sulfate, C2H6O4S (CH3O)2SO2, corrosive, oily, onion-like odour, heat fumes, Toxic by all routes, Not permitted in schools.
Dimethyl sulfide (CH3)2S, DMS, methylthiomethane, volatile, insoluble, inflammable, offensive sweet smell, in flatus and smell of the sea.
Dimethyl sulfoxide, C2H6OS (CH3)2SO), DMSO: 16.2.8.9.
Dimethyl trisulfide, DMTS, CH3SSSCH3, volatile, bad odour from cooked Brassicaceae vegetables, boiled cabbage smell.
Dimethylamine
, C2H7N.

Diosmetin
Diosmetin, C16H12O6, flavonol, yellow, antioxidant, inhibits carcinogen activation enzyme CYP1A1
in peel of Lemon (Citrus x limon), Rutaceae.

Dioxane
Dioxane, C4H8O2, 1, 4-dioxane, cyclic ether, solvent miscible with water, Toxic, Use very small amounts
Dioxane, Solution < 1%, Not hazardous

Diphosphane, P2H4
Diphosphane, P2H4 (formerly diphosphine), very toxic, as impurity causes phosphine to ignite in air
Phosphine, PH3
Fluorophores: 14.3.0a
Direct union of elements
Direct union of elements to form compounds: 8.0.0
Prepare salts by direct union of elements: 4.0
Synthesis reactions (combination reactions, direct union of elements): 12.2.2.0

Disodium hydrogen phosphate
Disodium hydrogen phosphate, Na2HPO4, sodiumphosphate dibasic, disodium phosphate, sodium hydrogen phosphate,
disodium hydrogen orthophosphate (V), sodium phosphate dodecahydrate, white monoclinic or rhombic crystals or granules,
r.d. 1.5, m.p. 34oC to 35oC, easily loses H2O, E339 (II), anticaking agent, retards boiler scale.

Displacement reactions
Displacement reactions (substitution reactions): 12.2.4.0
Displace a less reactive halogen from halogen compounds: 12.19.3.0
Electrical energy from the displacement of copper by zinc: 3.84
Heat of displacement reaction, zinc with copper (II) sulfate solution: 14.1.6
Heat of reaction, metals displace copper: 3.83
Iron displaces copper in copper sulfate solution: 12.2.4.1
Magnesium displaces copper from solution of copper ions: 3.72
Magnesium displaces hydrogen in ethanoic acid: 12.2.4.3
Metals displace hydrogen from acids: 3.74
Prepare zinc sulfate crystals: 12.2.4.2
Zinc displaces lead from lead nitrate solution: 12.14.1

Dissolve
See: Dissolving (Commercial)
Dissolve (See above: 12.7.7.1 Alkalis with zinc sulfate solution)
Total dissolved solids and suspended solids in water, Beer-Lambertlaw: 18.2.0
"Magnetic" sugar cube dissolves: 3.17.1
Volume change when substances dissolves: 3.3.4

Distil, distilled, distillation
See: Distilling (Commercial)
Distil crude oil and collect the fractions, combustion of gasoline, alkylation: 10.6.3
Distil wood (destructive distillation): 16.10.4.1
Distilled water, deionized water: 6.3.1.3
Prepare gas by destructive distillation of coal: 10.6.5
Separation using distillation: 10.5.0
Separate by fractional distillation: 10.6.0
Steam distillation of eucalyptus leaves: 10.5.6
Steam distillation to measure water and fat content of food: 10.5.5
Water stills: 2.5 (Safety)

Dodecyl benzenesulfonic acid
Dodecyl benzenesulfonic acid, C18H30O3S, nansa acid, Toxic if ingested

Double decomposition, double replacement, double exchange reactions
Double decomposition, double replacement, double exchange, metathesis, precipitation, neutralization reactions: 12.2.1.0
Precipitation reactions, prepare salts: M3
Prepare insoluble hydroxides with ammonia solution, double decomposition: 3.33.2.1
Prepare soap by saponification: 12.12.02

Double salt
Aluminium potassium sulfate
Fehling's test: 9.142.0
Prepare copper (II) ammonium sulfate crystals: 12.7.4
Prepare double salt crystals: 3.54.01
Prepare iron (II) ammonium sulfate: 14.8.14
Prepare potash alum from its constituent salts: 12.14.1
Rochelle salt, potassium sodium tartrate-4-water

Dyes, pigments
Dyes, reactive dyes, direct dyes, acid dyes, mordant dyes, metrolene dyes, dye intermediates, pigments
Dyes, Prepare plant dyes (Primary): 3.30
Dyes with a mordant: 19.5.3
Dyes, solvent-based, aniline, diazo, naphthol, water-based, fabric, wool
Leuco dyes, Thermochromism, Colour Changing Ducks: (Commercial)
Mordants
Pigment names, C.I. numbers: 8.0 (Table)
Separate by chromatography, pigments from green leaves: 3.24.0

Dubnium
Dubnium
, Db (Dubna, Nuclear Institute, Russia), radioactive transuranic element

3.6.1 Deuterium
Deuterium, D or Hydrogen-2, 2H, hydrogen isotope having a proton and a neutron in the nucleus
Deuterium oxide, D2O, water with H replaced by D
Deuterium exchange, organic compound
ROH + D2O --> ROD + DHO, used in NMR spectroscopy toidentify position of H.

Dysprosium
Dysprosium
, Dy (Greek dusprositos hard to find) (future supply shortfall, the Dy-Te-Fe alloy, Terfenol D)
Dysprosium is an essential component for magnets for turbines and electric motors, because by adding Dysprosium
to the magnet allows the magnetism to be retained, even at very high temperatures.
Most Dysprosium is mined in China, but lately it is mined in Australia.
Dysprosium chips, foil, ingot, Dy
Dysprosium (III) acetate, C6H9DyO6.xH2O
Dysprosium (III) bromide hydrate, Br3Dy.xH2O
Dysprosium (III) carbonate hydrate, C3Dy2O9.xH2O
Dysprosium (III) chloride hexahydrate, Cl3Dy.H2O
Dysprosium (III) fluoride anhydrous, DyF3
Dysprosium (II) iodide anhydrous, DyI2
Dysprosium (III) nitrate hydrate, DyN3O9.xH2O
Dysprosium (III) oxide, nanoparticles, Dy2O3
Dysprosium (III) perchlorate, Cl3DyO12
Dysprosium (III) trifluoromethanesulfonate, C3DyF9O9S3
Desiccants, drying agents
See diagram 3.31.04: Drying agents
Desiccants are drying agents, e.g. anhydrous calcium chloride, anhydrous calcium sulfate, concentrated sulfuric acid, phosphorus (V)
oxide, sodium hydroxide lump, calcium oxide lump (lime), silica gel.
Glass desiccators used to dry chemicals in the laboratory may havea tap in the lid to increase evaporation by decreasing pressure in
the desiccator.
Glass desiccators can also preserve organic materials by desiccation.
Desiccants, drying agents, are used where drying by heating may decompose the substance to be dried.
Drying agents, desiccants, may just absorb water into their surfacestructure, e.g. silica gel.
Dry silica gel is hygroscopic. It absorbs water from the air, but does not dissolve in the water.
Little white bags containing silica gel desiccant are often included in electrical equipment and other products just before the close of
the manufacturing process.
Powerful desiccants may remove water by a chemical reaction, e.g. concentrated sulfuric acid.
Concentrated sulfuric removes the water of crystallization from blue copper sulfate crystals to form white anhydrous copper sulfate
CuSO4.5H2O --> CuSO4+ 5H2O
Concentrated sulfuric acid removes water from the white to colourless sucrose molecules to leave black carbon.
C12H22O11 --> 12C + 11H2O
However, concentrated sulfuric acid is a powerful acid and oxidizing agent so it must be used with great care.
Laboratory desiccators are usually heavy glass containers sealed with a ground glass lid lubricated with Vaseline to make the
container air tight.
The substance to be dried is on a watch glass on a shelf above thedesiccant.
The base of the desiccator may contain various desiccants:
1. Phosphorus pentoxide,
2. Anhydrous magnesium sulfate,
3. Melted caustic potash (potassium hydroxide),
4. Concentrated sulfuric acid (it turns black with time),
5. Silica gel,
6. Anhydrous calcium oxide,
7. Anhydrous calcium chloride,
8. Anhydrous zinc chloride,
9. Anhydrous copper sulfate.
Phosphorus pentoxide is a much more powerful drying agent then anhydrous copper sulfate.
The desiccator may be used as a suitable cooling vessel so that thesubstance can cool yet not at the same time absorb water from
the atmosphere.
Some liquids, e.g. organic compounds, may be dried by dropping in calcium chloride that is removed hours later by a glass wool filter.
Gases are dried by passing the damp gas through an U-tube or glasstower containing anhydrous calcium chloride between glass
wool plugs with airtight taps at each end.
Gases can be dried by bubbling through concentrated sulfuric acid but some acid droplets get carried into the dried gas.
To avoid acid droplets, the sulfuric acid can be absorbed into lumps of pumice that are then used in a glass drying tower.
Drying gases is usually a very slow process.
Table: Desiccants, drying agents
Gas to be dried
Drying agent
Ammonia
Calcium oxide
Carbon dioxide
Any in this column
Carbon monoxide
Phosphorus pentoxide
Chlorine
Concentrated sulfuric acid
Hydrogen
Calcium chloride
Hydrogen chloride
Concentrated sulfuric acid
Hydrogen sulfide
Calcium chloride
Nitrogen
Calcium chloride
Nitrous oxide
Concentrated sulfuric acid
Oxygen
Phosphorus pentoxide
Sulfur dioxide
Any in this column