Chemistry topics starting with D

School Science Experiments
Chemistry
2025-10-28
Chemistry, D
Contents
Dacron
Daguerreotype, (Experiment)
Dalapon, (Agriculture)
Dalton's law of partial pressures
Daminozide, (Agriculture)
Daniell cell, (Experiments)
Danielone
Dantron
Darlingine
Darmstadtium, Ds
Date rape drugs, Rohypnol, GHB, Ketamine
DCPA
DCPIP, (Experiments)
2,4-D, (Agriculture)
DCIP solution, Prepare
DCMU, (Agriculture)
DDT
DEA list of chemicals
Debneyol
Decalcifying solution, Prepare
Decanal
Decanedioic acid
Decanoic acid
Decanolactone
Decanting, Separate
Decarboxylation, removing carboxyl group from compound
deci, one tenth, e.g. decilitre = 1/10 litre
Decoctions, Prepare
Decomposition reactions, (Experiments)
Decrepitation, Tests
DEET
Degrees proof, proof spirit
DEHP
De-icers, Ice melts
Deidaclin
Deionized water, Distilled water
Delafield's haematoxylin, Prepare
Delcosine
Deliquescent, substances, (Experiment)
Delphinidin
Delphinine
Delsoline
Deltaline
Depo-Provera
Demecolcine
Demethylcoclaurine
Demethoxypiplartine
Demethyldeoxypodophyllotoxin
Demineralized water, Deionized water
Denatured
Dendrobine
Density, (Experiments)
Denudatine
Deoxykaempferol
Deoxylactucin
Deoxyribose
Depression FP, (Experiments)
Derris, Rotenone, (Agriculture)
Deserpidine
Desiccants, Safety
Designer drugs
Deslanoside
Desacetoxymatricarin
DETE
Detergents, (Experiments)
Dettol, (See: 1.)
Deuterium
Devarda's alloy
Dewar flask (Physics), (Experiments)
Dexchlorpheniramine, (See: Antihistamines)
Dextran
Dextrins, (Experiments)
Dextrose, (Experiments)
DHB
Dhurrin
Diacetyl
Diallyl disulfide
Diallyl sulfide
Diallyl trisulfide
Dialysis, (Experiments)
Diamino compounds
Diammonium compounds
Diamond (Experiments)
Diastase activity, Tests
Diatomaceous earth
Diazepam, (Valium), (TN)
Diazines: Pyrizine, Pyridizine, Pyrimidine, (gif)
Diazo compounds
Diazo prints (Experiments)
Diazonium ion, C6H5N2+
Dibromo
Dibutyl phthalate
Dicarbides, Calcium dicarbide, Safety
Dicarboxylic acids
Dichlor, swimming pools
Dichloro-
Dichlorvos, Agriculture
Dichromate ion Cr2O72-
Dichromates, (Experiments)
Dichromatism
Dicofol
Didrovaltratum
Dienes, Prepare ethene
Diesel fuel, (Experiments)
Diethanolamine
Diethyl
Differentiation solution, Prepare
Diffusion, particles of matter, (Experiments)
Diffusion, colloids
Digiferrugineal
Diginatin
Digitalose
Dihydrochalcones
Dihydrocubebin
Dihydrocaffeic acid
Dihydrokarvain
Dihydromethysticin
Dihydrosanguinarine
Dihydroxyacetophenone
Dihydroxyacetone
Dihydroxyflavan
Digitoxigenin
Digitoxin
Digoxin
Diindolylmethane
Dioscorine
Dilatant fluids, shear-thickening fluids
Dilead (II/IV) oxide
Dill ether
Dillapiole
Dilute, Prepare
Dilution, Prepare
DIMBOA
Dimercury (I) chloride, Calomel, (Geology)
Dimethylamine
Dimethyltryptamine
Dimorphism, Argonite, (Geology)
Dinitrogen monoxide, Nitrous oxide, (Experiments)
Dinitrogen tetroxide, Nitrogen dioxide, (Experiments)
Dinoseb, (Experiments)
Dioscorine
Diosmetin
Diosphenol
Dioxane
Dioxins, "Agent orange"
Dipentene
Diphosphane P2H4
Dipsticks, vitamin C test
Direct union of elements
Disaccharides
Disappearing ink
Discharge tubes, Gas
Dishwashing liquids, Herbicides
Disinfectants, antiseptics and antibiotics, (Biology)
Disodium orthophosphate
Disodium tetraborate, Borax, (Experiments)
Disogenin
Displacement reactions, (Experiments)
Disproportionation, Hydrogen peroxide with catalase, (Experiments)
Dissociation constant, Ka
Dissolve, (Experiments)
Dissolved oxygen, Winkler
Distil, Distillation, (Experiments)
Diterpenes, Diterpenoids
Diterpene alkaloids
Dithizone
Diuron, DCMU, (Agriculture)
dm3 = 1 litre
DMSO, Dimethyl sulfoxide, Sulfoxide
DNA and RNA , (Biology), (Experiments)
Docetaxel, Taxotere
Dodecane
Dodecanoic acid, Lauric acid, (Experiments)
Dodecanol, Lauryl alcohol
Dolomite, (Geology)
Domestos solution, Prepare
Dopa, Levodopa, L-dopa
Dopamine
Double decomposition, (Experiments)
Double salt, (Experiments)
Doxorubicin
DPD test for swimming pools, diethyl-paraphenylene diamine, C10H16N2
DPX mountant, Prepare
Drain cleaners, Drano
DRBC agar, Prepare, (food spoilage)
Drink can, beverage can, (Experiments)
Drinking bird heat engine, drinking duck, dippy bird, (Experiment)
Drinking straws soda straws, "straws", (Experiments)
Drinking water test media
Drug abuse
Drugs, water fleas, (Daphnia pulex)
Dry cell, Electric torch, (Flashlight), battery
Dry cleaning spirit, (White spirit)
Dry ice, CO2, (Experiments)
Drying agents, Desiccants
Dubnium, Db
Ductile, (Physics)
Duplicating fluid, Methylated spirits
Dust explosions, (Safety)
Dust masks, (Safety)
Dusts, sprays, white oils, (Agriculture)
Duties of a teacher
Dyes pigments, (Experiments)
Dynamite, Nitroglycerine
Dysprosium, Dy

DEHP
DEHP, C24H38O4, di-(2-ethylhexyl)phthalate, polyvinyl chloride resin plasticiser

Deidaclin
Deidaclin, C12H17NO6, cyanogenic glycoside It occurs in Tetrapathaea tetrandra (New Zealand), Kiggelaria africana, Passiflora foetida.

Demineralized water
Demineralized water, "demi water", minerals or salts removed, replaces expensive distilled water.

Denatured The structure of a protein collapses, is denatured, by heating or oxidation or acid or agitation in air.
16.6.8 Denatured alcohol, methylated spirits

Depression
Freezing point depression and boiling point elevation: 24.4.1
Freezing point depression of carbonated water, cola: 24.4.3

Diazepam
See diagram: Diazepam
Diazepam, (Valium), C16H13ClN2O, 1,4-benzodiazepinone, white-yellow crystalline powder, almost odourless, tasteless then bitter aftertaste.
It is an anti-anxiety drug, anticonvulsant, sedative, but it has a low potential for drug abuse.

Dibutyl phthalate
Dibutyl phthalate, C16H22O4, DPB, plasticiser, food contaminant, colourless, oily liquid, weak odour
It is used to make plastics more flexible, is not a natural product and is regarded as an environmental contaminant.

Dichlorvos
Dichlorvos, C4H7Cl2O4P, CCl2=CHOPO(OCH3)2, once used widely, but now banned for plant protection product in the EU.
It is an insecticide, dense colourless liquid, sweet smell, mixes with water and was used for insect control in food storage areas and on pets.
If heated to high temperatures, emits toxic chloride fumes and phosgene gas, and is toxic by inhalation.

Diginatin
Diginatin, C41H64O15, Diginatigenin 3-O-tridigitoxoside, cardenolide glycoside
It occurs in Digitalis lanata.

Dihydrocubebin
Dihydrocubebin, C20H22O6, glycol, lignan, butanediol, benzodioxole, antimicrobial
It occurs in Podolepis rugata, Horsfieldia irya, Horsfieldia bark, leaves, and wood.

Dihydrokarvain
Dihydrokarvain, C14H16O3, kavalactone, anxiolytic
It occurs in Piper methystichum, kava.

Dihydromethysticin
Dihydromethysticin, C15H16O5, 2-pyranone, quinone, aromatic ether, spasmolytic, It occurs in Piper methysticum, Piper majusculum, and in Aniba hostmanniana

Danielone
Danielone, C10H12O5, an acetophenone, aromatic ketone, phytoalexin, antifungal activity
It occurs in Papaya species fruit, Cestrum parqui, and in Euglena gracilis.

Dantron
Dantron, C14H8O4, chrysazin, (1,8-dihydroxyanthraquinone), health hazard, former laxative
It is an orange crystalline powder, odourless, tasteless, immunosuppressive, cathartic, purgative, antioxidant, and fungicide.
It is a possible carcinogen, but withdrawn from US markets due to genotoxicity, and it causes red urine.
It occurs in Cassia species, Rheum species, Xyris species leaves and stems, and in Cinchona species.

Darmstadtium, Ds
Darmstadtium, Table of the Elements
Darmstadtium, RSC
Darmstadtium, Ds ( German Darmstadt, where it was first produced in Germany), radioactive transuranic element.

DCPIP
DCPIP, C12H7NCl2O2, dichlorophenolindophenol, dichloro-indophenol, dichlorophenol solution, tablets, toxic
2,4-Dichlorophenoxyacetic acid, 2,4-D, herbicide: 4.4.1
Prepare DCIP solution: 7.16
Tests for vitamin C (L-ascorbic acid): 9.3.21
Toxicity, Poisons and First Aid: 1.0H, (Table)

Decomposition reactions
12.2.2 Decomposition reactions
15.5.4 Electrolysis of water
12.11.3.4 Tests for substances, sublimation, melting, decrepitation
3.7.0 Thermal decomposition, List

12.19.4.1 Daguerreotype
A 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 it 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 from the plate.
To leave 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 protect them from tarnishing of the silver.
Old daguerreotypes may be damaged by salts from sea air and spotlights.

DEET, C12H17NO
DEET, C12H17NO, N,N-Diethyl-meta-toluamide, diethyltoluamide, "PESTANAL", common in pesticides
I gives short-term protection against Anopheles species mosquitoes, rather than Culicine mosquitoes.
DEET: See diagram16.13.8

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 C6H8O7, (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.
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.

Delphinidin
Delphinidin, Anthocyanin, Hexahydroxyflavylium, C15H11O7+, antineoplastic, blue pigment
It occurs in Viola species, Delphinium species, Vitis vinifera, (grape), and Vaccinium species, (cranberry).
See diagram: Delphinidin cation
Delphinidin 3-O-glucoside, C21H21O12
Delphinidin chloride, C15H11ClO7, pigment, in grape, in cranberry, in pomegranate

Delsoline, C25H41NO7
Delsoline, Acomonine, Belsoline, a diterpenoid, may cause convulsions and respiratory depression
It occurs in Delphinium consolida, and in Aconitum monticola

Demethyldeoxypodophyllotoxin, C21H20O7
Demethyldeoxypodophyllotoxin, lignan, gamma-lactone, a methoxybenzene, phenol, immunosuppressive, antioxidant, antineoplastic, antimimetic, antileukemic
It occurs in Polygala paena roots, and in Hyptis verticillata

Demethoxypiplartine, C16H17NO4,
Demethoxypiplartine, (3'-Demethoxypiplartine), it is a phenylpropanoid.
It occurs in Piper tubercalatum

Deoxykaempferol, C15H10O5
Deoxykaempferol, (3,7,4'-Trihydroxyflavone), (5-Deoxykaempferol), chemopreventive effect on UVB-induced skin, carcinogenesis
It occurs in Cicer arietinum, (chickpea).

Detergents
7.4.19 Detergent, SYNDET, Synthetic Detergent
Detergents in rivers and lakes
Effect of detergents on freshwater organisms: 18.7.4
Hardness in water, water hardness: 12.2.0
Soaps and synthetic detergents: 12.5.0
Surfactants: 12.6.0
Water glass: : 7.8.9

Devardas alloy
Devardas alloy, AlCuZn, powder, 50% Cu, 45% Al, 5% Zn, tests for (NO3)-
Experiment
Reduce nitrate to ammonia
Add 3 small crystals of sodium nitrate to 3 cm of dilute sodium hydroxide solution.
After the sodium nitrate dissolves, add Devardas alloy.
The reaction with NaOH is strongly exothermic.
Heat the solution and test for ammonia.

Dextran, H(C6H10O5)xOH
Dextran, 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, low molecular-weight carbohydrates produced by the hydrolysis of starch or glycogen.
Dextrins are mixtures of polymers of D-glucose units linked by glycosidic bonds.
Tests for dextrins in toast: 19.2.14
Prepare glucose with starch: 16.7.15

Diamond
Diamond: 35.3.3, (Geology)
Diamonds (Total internal reflection): 28.6.4, (Physics)
Glass knife (ceramic impregnated with diamond dust)
Hardness, Mohs' scale of hardness: 34.10.0, (hardness 10. diamond)
Lustre, (metallic and non-metallic lustre): 35.1.9, (Geology)
Measure refractive index: 28.125, (Diamond n = 2.4173)

Dibromo
6.00 Bromocresol purple
7.01 Bromophenol red
8.00 Bromothymol blue
16.14.1 PBDE, pentabromodiphenyl ether, C12H5Br5O
12.6.16 Ethylene dibromide, 1,2-Dibromoethane
12.6.17 Dibromomethane, methylene bromide
12.6.18 Dibromopropane

Dichloro
Dichlor, dichloroisocyanuric acid, dichloro-s-triazinetrione, (C(O)NCl)2(C(O)NH).
Dichlor: 18.1.7, swimming pools
Dichlorobenzene, C6H4Cl2
Dichloroacetic acid, CHCl2COOH
Dichlorobiphenyl
Dichlorodifluoromethane, CCl2F2
Dichloroethane, Cl(C2H4Cl
Dichloromethane, CH2Cl2
Dichlorophenolindophenol, 2,6-dichlorophenolindophenol
(2,4-D), (2,4-dichlorophenoxyacetic acid): 4.4.1 (Weedicide), (Agriculture)

DDT, C14H9Cl5
DDT, insecticide, New IUPAC name: 1,1'-(2,2,2-Trichloroethane-1,1-diyl)bis(4-chlorobenzene)
See diagram 16.3.4.0.6: DDT, methoxychlor
Synergists: piperonyl butoxide
Aromatic halogen compounds: 16.2.9
DDT: 4.8.1, Agriculture
Dioxins, Agent orange, PCBs: 16.15.0 (See 2.)
Pediculosis, lice, louse, infection, Phthirus pubis: 5.2.14

Diamino
Diamino compounds contain 2 amino groups or substituted amino groups, e.g. Diaminoethane, C2H4(NH2)2

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,
1,2-Diaminoethane, Solution < 1%, Not hazardous

Diaminobiphenyl
Diaminobiphenyl, C12H12N2, C6H4(NH2)2, (4,4'-diaminobiphenyl benzidine), toxic by all routes, Not permitted in schools

Diaminobutyric acid
Diaminobutyric acid, C4H10N2O2, a diamino acid, non-proteinogenic alpha-amino acid, potent antitumoral activity against human glioma cells

Diaminohexane
Diaminohexane, C6H16N2, H2N(CH2)6NH2, (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
Diatoms, Phylum Bacillariophyta: 9.3.1
Diatomaceous earth absorbacide: 4.7.4, (Agriculture)
Filters (Swimming pools): 18.4.7
Nitroglycerine (UK), Nitroglycerin (USA): 16.6.10

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
1,2-dichlorobenzene, o-dichlorobenzene, toxic, avoid inhalation of vapour
1,2-dichlorobenzene. Solution < 5% Not hazardous
1,4-Dichlorobenzene, C6H4Cl2, MP. 53oC, crystalline, p-DCB, para-dichlorobenzene, 1,4-dichlorobenzol, toxic if ingested, colourless strong odour
It is used as a deodorant, (solid blocks deodorant in male toilets), pesticide, suitable replacement for naphthalene mothballs
Use ethanol to prepare dilute solutions
1,4-dichlorobenzene, Solution < 25%, Not hazardous
Reaction of chlorine with benzee: 12.4.6.1, Halogenation of benzene
Melting point of 1,4-dichlorobenzene: 3.3.7
(However, substitute hexadecan-1-ol for melting point curve experiments.)

Dichlorobiphenyl
Dichlorobiphenyl-4, (4'-diamine), (3,3'-dichlorobenzidine), toxic by all routes, Not permitted in schools, (2,2'-dichlorodiethyl) ether

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

Dichloroethane
Dichloroethane, Cl(C2H4Cl, (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 chlorinated solvents, e.g. trichloroethane, to remove grease, resins, glue and dirt, "anti-knock" compound in leaded petrol.

Dichloromethane, CH2Cl2
Dichloromethane, CH2Cl2, methylene chloride, methylene dichloride, Freon 30, toxic by all routes, possibly carcinogenic
Dichloromethane, Solution < 1%, Not hazardous
Colourless liquid, BP 41oC (refrigerant, degreasing, cleaning fluid, paint strippers, solvent), ozone-depleting chemical so use very small amounts.
Use ethanol as solvent for dilute solutions.
Organic solvent, in paint strippers, low BP of 39.6oC.
1.0 Poisons, First Aid, (See: Dichloromethane, CH2Cl2)
24.3.6 Drinking bird heat engine
9.2.2 Caffeine, extraction with supercritical carbon dioxide
16.5.1.3 Methane with chlorine, (Dangerous experiment!)
14.21 Methylene chloride
19.3.4 Paints, safety advice for paints and paint strippers, (See: 7. Safety advice)
3.3.7 Prepare nylon polymer, (See: Experiment 3.)

Dichromates
Dichromates, ( - Cr2O7-), strong oxidizing agents, e.g. potassium dichromate K2Cr2O7, usually orange-red salts
Sodium dichromate, red-orange crystals, SG 2.35, soluble in water
Sodium dichromate, insoluble in alcohol. If heated to decomposition, emits toxic fumes of sodium monoxide
Chromic acid, ionization reaction, H2CrO4:
H2CrO4 + H2O --> H3O+ + HCrO4-, K1 = 2 × 10-1
HCrO4- + H2O --> H3O+ + CrO42-, K2 = 3.2 × 10-7
Chromates, dichromates, hazards: 3.7.4
Chromic acid, Ionization reactions: 12.8.7
Oxidize chromium compounds to chromates, CrO42-: 12.8.5
Potassium dichromate, K2Cr2O7
Reactions of dichromates, potassium dichromate: 12.8.3

Diesel fuel
Adiabatic change, thermodynamics: 20.4.4
Ammonium nitrate, diesel / ammonium nitrate mixtures, Not permitted in schools
Diesel oil: 16.8.1, Fractional distillation of crude oil
Fuels, fuel cell
Separate by fractional distillation: 10.1.5

Diethyl, -(C2H5)2
Diethyl ketone, pentan-3-one
Diethyl sulfate, toxic by all routes, Not permitted in schools
Diethylamine, C4H11N, plant amine
Diethylaminopropylene, DMAPA, curing agent for epoxy resin adhesive, surface coating, irritant
Diethyl ether
Diethylphenylenediamine, C10H16N2
Diethylene glycol, C4H10O3, DEG (cosmetics, photography developer), toxic
Diethylenetriamine, C4H13N3, NH2CH2(CH2)2NH, DTA, tridentate ligand, curing agent for epoxy resin adhesive, surface coating, Irritant

Diethyl ether
Diethyl ether, C4H10O, 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%, contains BHT as inhibitor
Diethyl ether forms dense vapour that flows along bench or floor to point of ignition
Diethyl ether, on standing forms diethyl peroxide, that is less volatile and remains an explosive residue

Diethylphenylenediamine
Diethylphenylenediamine, C8H12N2, toxic by all routes
N,N-diethyl-p-phenylenediamine, Solution < 3%, Not hazardous

Digiferrugineal
Digiferrugineal, Digiferruginol, C15H16O5, an anthraquinone, cytotoxic to human nasopharynx carcinoma, phytoalexin, antimicrobial.
It occurs in Streptocarpus, in Digitalis, in Morinda parvifolia, in Cinchona.

Dihydrocaffeic acid
Dihydrocaffeic acid, C9H10O4, 3,4-Dihydroxyhydrocinnamic acid, hydrocaffeic acid, a monocarboxylic acid, antioxidant
It occurs in normal human biofluids, improves platelet function, in human plasma after coffee ingestion, in artichoke leaf extract

Dihydroxyacetone
Dihydroxyacetone, C3H6O3, 1,3-Dihydroxy-2-propanone, irritant, a ketotriose, a primary alpha-hydroxy ketone, antifungal agent
It is used in addition to blood preservation solutions to improve blood storage.
It is used with naphthoquinones as a sunscreening agent, because it stains skin brown, but no increase in melanin so is used in sunless tanning, i.e. fake sun tan.
Sold as: Dihydroxyacetone, 1,3-Dihydroxy-2-propanone, DHA, Glycerone
It occurs in Arabidopsis thaliana, and in humans.

Dihydroxyacetophenone
Dihydroxyacetophenone, Acetopyrocatechol, C8H8O3, phenolic ketone, an acetophenone
Amixture of dihydroxyacetophenone isomers used in food flavouring, inhibits platelet aggregation.
It occurs in Ilex pubescens, Picea needles, and in coffee residues

Dilution
Dilution equation: C1V1 = C2V2
Concentration (start) X Volume (start) = Concentration (final) X Volume (final)
Dilute solutions: 5.4.2
Colour change of diluted potassium permanganate: 11.3.3
Dilute acids with: 12.4.0
Particles: 11.6.0, (Experiments)
Prepare dilute acids: 5.4.7
Prepare dilute acids and bases (Safety instructions): 3.4.10
Prepare dilute bases: 5.4.8
Prepare serial dilutions: 12.0

DIMBOA
DIMBOA, C9H9NO5, (4-benzoxazinone), an allelochemical (toxic plant defence chemical), aromatic ether, cyclic hydroxamic acid
It occurs in cereals and cereal products.
It is an insecticide and fungicide.

Dimethylamine
Dimethylamine, (CH3)2NH or C2H7N, N-Methylmethanamin, secondary aliphatic amine, liquefied and flammable colourless gas
DMA, [NH = imino group], fish odour, increase in human urine after fish diet
It is used in soaps, fungicides, dehairing of skin and hides, tanning, dyes, rubber accelerators, soaps, cleaning compounds, and agricultural fungicides
Dimethyl-3-octanol, C10H22O, monoterpene, colourless liquid, flavouring ingredient, perfume, tetrahydrolinalool
Dimethyl aminoazobenzene-4-sulfonate, C12H11N3, 4-aminoazobenzene, aniline yellow, orange powder, salts used for azo dyes
Dimethyl aniline, C8H11N, (CH3)2C6H3NH2, C6H5N(CH3)2, (4-dimethylaniline)
Dimethyl benzene C6H4(CH3)2, C8H10, one of 3 isomers is Xylene, 1,3-Dimethylbenzene
Dimethyl disulfide, C2H6S2, DMDS, volatile, offensive garlic-like odour in bad breath, in municipal solid waste landfill
Dimethyl formamide C3H7NO or HCON(CH3)2, DMF, (N,N,dimethylformamide), solvent, paint thinner, odourless, but fish smell if impure
Dimethyl polysiloxane (C2H6OSi)n, polydimethylsiloxane, PDMS, food additive E900
Dimethyl sulfate, C2H6O4S, corrosive, oily, onion-like odour, heat fumes, toxic by all routes, Not permitted in schools
Dimethyl sulfide, C2H6S, DMS, methylthiomethane, volatile, inflammable, offensive sweet smell, in flatus and smell of the sea
Dimethyl sulfoxide, C2H6OS, (CH3)2SO), DMSO: 16.10.12
Dimethyl trisulfide, DMTS, CH3SSSCH3, volatile, bad odour from cooked Brassicaceae vegetables, boiled cabbage smell

Diosmetin
Diosmetin, C16H12O6, Flavonol, (4'-methyl ether), Salinigricoflavonol, trihydroxyflavone
It is a yellow, antioxidant, antineoplastic, antimicrobial, oestrogenic, anti-inflammatory, inhibits carcinogen activation enzyme CYP1A1
It occurs in peel of lemon, and in other citrus fruits

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

Diphosphane
Diphosphane, P2H4 (formerly diphosphine), very toxic, as impurity causes phosphine to ignite in air
Phosphine, PH3
Fluorophores: 14.26

Disodium orthophosphate
Disodium orthophosphate, disodium hydrogen phosphate, Na2HPO4, sodium phosphate dibasic, disodium phosphate, sodium hydrogen phosphate
It has white monoclinic or rhombic crystals or granules, RD. 1.5, MP. 34oC to 35oC, easily loses H2O, E339
It is used as anticaking agent, and to retard boiler scale

Dissolve
Total dissolved solids and suspended solids in water, Beer-Lambert law: 18.2.0
"Magnetic" sugar cube dissolves: 3.6.2
Shrinking volume: 3.5.0
Volume change when substances dissolve: 11.3.9
Tests for dissolved oxygen, DO (Winkler method): 18.3.2

Distillation
Coal tar products, creosote: 16.4.0
Distil crude oil and collect the fractions, combustion of gasoline, alkylation: 10.3.9
Distil wood: 16.10.4.1, (destructive distillation of wood)
Prepare distilled water: 2.2.14
Distilled water, deionized water: 6.3.1.3
Separation by distillation: 10.3.0
Steam distillation of eucalyptus leaves: 10.3.10
Steam distillation to measure water and fat content of food: 10.3.11
Water stills: 2.2.13 (Safety)

Dithizone
DithizoneH, C13H12N4S, C6H5NHNHCSN=N(C6H5), dithiozone, dithizon, diphenyl thiocarbazone, phenylhydrazine.
Chelating agent used for heavy metal poisoning and assay, causes diabetes, toxic if ingested.

Dodecane
Dodecane, C12H26, CH3(CH2)10CH3, from Zingiber officinale essential oil

Double decomposition
Double decomposition, double replacement, double exchange reactions
12.2.4.0 Double replacement reactions, metathesis
Prepare hydroxides with ammonia solution: 3.2.1
Prepare soap by saponification: 12.12.02

Double salt
13.1.13 Aluminium potassium sulfate
Fehling's test: 9.5.0, Rochelle salt is a double salt
Prepare copper (II) ammonium sulfate crystals: 12.7.4
Prepare double salt crystals: 3.1.11
Prepare iron (II) sulfate crystals with iron filings: 14.15.18
Prepare potash alum: 12.14.2
Rochelle salt, potassium sodium tartrate-4-water
33.88 Leclanché cell

Doxorubicin
Doxorubicin, Adriamycin, Doxil, Adriablastin, C27H29NO11, anthracycline antibiotic, antineoplastic, (from Streptomyces peucetius var. caesius),
It prevents DNA replication, inhibits topoisomerase II..
It has cardiac and cutaneous vascular effects, and is used for lymphoma therapy..

Dyes
Dyes, pigments, reactive dyes, direct dyes, acid dyes, mordant dyes, metrolene dyes, dye intermediates, pigments
Dyes, Prepare plant dyes (Primary): 3.30
Dyes with a mordant: 19.4.2
Dyes, solvent-based, aniline, diazo, naphthol, water-based, fabric, wool
Leuco dyes, Thermochromism, Colour Changing Ducks: (Children's item)
Mordants
Pigment names, C.I. numbers: 8.0 (Table)
Plant pigments
Anthocyanidins, Anthocyanins
Betalains, betains
Carotenoids, Tetraterpenoids, (C40H64)
6.6.1 Photosynthetic pigments, chlorophyll a and chlorophyll b
Mazari palm, India, kaki, plant roots,
Butternut tree, Colombia
Mingonette, weld, Europe, Middle east. yellow
Turmeric, sari robes, India
Saffron , vibrant yellow
Pale green, boil yellow fabrics in iron bowl
Light green, stinging nettle
Lincon green, woad blue + woad yellow
Green blue + yellow
Licen Lobaria oregana, Nw pacific, sofy purple
Muuberry, purple
Murex snails,Tyrian purple
Woad, blue, Europe
Mayo ondigo, anil. Colombia, indigo
Chinese indigo, buckwheat, blue
blue indigophora<
Kermes insects, crimson, Med
Madder, red. India Cochineal, crimson
Ochre, iron, haematitie

Dubnium, Db
Dubnium, Table of the Elements.
Dubnium, RSC
Dubnium, Db (Dubna, (Nuclear Institute, Russia), radioactive transuranic element.

Deuterium, 2H
Deuterium, D or Hydrogen-2, 2H, is a hydrogen isotope having a proton and a neutron in the nucleus..
Deuterium oxide, D2O, is water with H replaced by D..
Deuterium exchange, organic compound.
ROH +D2O --> ROD +DHO, is used in NMR spectroscopy to identify position of H..
Heavy water has the hydrogen in the water molecules replaced by the isotope deuterium, and is used as a moderator in nuclear reactors..

Dysprosium, Dy
Dysprosium, Table of the Elements
See: Dysprosium, RSC
Dysprosium, Dy, (Greek dusprositos hard to find), (future supply shortfall, the Dy-Te-Fe alloy, TerfenolD)
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 |

Desiccants
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
Also, sodium hydroxide lump, calcium oxide lump (lime), silica gel.
Glass desiccators used to dry chemicals in the laboratory may have a 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 surface structure, e.g. silica gel.
Dry silica gel is hygroscopic, absorbs water from the air, but does not dissolve in the water.
Little white bags containing silica gel desiccant are 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
Be Careful! 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 placed on a watch glass on a shelf above the desiccant.
The base of the desiccator may contain various desiccants: | Anhydrous calcium oxide | Anhydrous calcium chloride | Anhydrous copper sulfate | Anhydrous magnesium sulfate | Anhydrous zinc chloride | Concentrated sulfuric acid, (it turns black with time) | | Melted caustic potash (potassium hydroxide) | Phosphorus pentoxide | Silica gel. |
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 the substance 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 gas through an U-tube or glass tower 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

Darlingine, (C13H17NO2), Tropane Alkaloid
Darlingine, oxacycle.
It occurs in Darlingea ferruginea
See diagram: Darlingine.

Delcosine, (C24H39NO7), Diterpenoid Alkaloid
Delcosine, Delphamine, Lucaconine, Delcosin, Iliensine, poisonous, insecticidal.
It occurs in Aconitum species. and in Delphinium consolida
See diagram: Delcosine.

Delphinine, (C33H45NO9), Diterpenoid Alkaloid
Delphinine, diterpene alkaloid, lycoctonine type, cardiovascular toxicity, dangerous herbal medicine, causes low blood pressure
It is used to treat disordered heart rhythms.
It occurs in | Candle larkspur, Delphinium elatum, Ranunculaceae | and in Staphisagria macrosperma, Ranunculaceae |.
See diagram: Delphinine.

Deltaline, (C27H41NO8), Diterpenoid Alkaloid
Deltaline, Delphelatine, eldeline, tertiary alcohol, tertiary amino compound, acetate ester, cyclic acetal, organic polycyclic compound
It occurs in Delphinium cheilanthum and Delphinium andersonii, , Ranunculaceae.
See diagram: Deltaline.

Demecolcine, (C21H25NO5), Colchicine Alkaloid
Demecolcine, Colcemid, Colchamine, Demecolcin, antineoplastic, arrests white blood cells in metaphase, mitosis spindle poison at metaphase, antitumour agent
It is less toxic than colchicine, and is used to inhibit growth of malignant cells.
It occurs in Autumn crocus, Colchicum autumnal, Alpine Autumn Crocus Colchicum alpinum, and Colchicum arenarium, Colchicaceae.
See diagram: Demecolcine.

Demethylcoclaurine, (C16H17NO3), Isoquinoline Alkaloid
Demethylcoclaurine, bisbenzylisoquinoline alkaloid, (norcochlorine, a conjugate base of a (RS)-norcoclaurinium), cardiac stimulant, "Higenamine"
It occurs in coffee and coffee products
It occurs in Aconitum Nelumbo nucifera, Delphinium caeruleum, in Berberis bealei
See diagram: Demethylcoclaurine.

Dendrobine, (C16H25NO2), Monoterpenoid and Sesquiterpenoid Alkaloid
Dendrobine, occurs in Dendrobium species, antiviral, antitumour, lowers blood pressure, may cause death by convulsions.
See diagram: Dendrobine.

Denudatine, (C22H33NO2), Diterpenoid Alkaloid
Denudatine, acute toxic, effects on action potential of ventricular fibres, inhibits arrhythmogenic action of aconitine
It occurs in Delphinium species.
See diagram: Denudatine.

Deserpidine, (C32H38N2O8), Indole Alkaloid
Deserpidine, Raunormine, Recanescin, Deserpidin, alkaloid ester, methyl ester, benzoate ester, yohimban alkaloid, anti-hypertensive
It causes decrease in blood pressure, tranquillizer.
It occurs in Rauvolfia canescens.
See diagram: Deserpidine.

Diethanolamine, Secondary Amine
Diethanolamine, [HN(CH2CH2OH)2], DEA, secondary amine (also "dialcohol", because two OH groups), weak base, oily colourless liquid or white crystals
It has a fish smell, is denser than water, and is used to make soaps, surfactants, dishwashing detergents, anticorrosion agent.
Diethanolamine (photography developer), Irritates skin and eyes.
Diethanolamine, Solution < 10%, Not hazardous
Diethanolamine bisulfite (photography developer), Irritates skin and eyes.

Diethylamine, (C4H11N), Secondary Amine
Diethylamine, [C4H11N(C2H5)2NH], (CH3-CH2-NH-CH2-CH3), diethyl amine, Toxic by all routes, Irritant to eyes, corrosive to eyes and skin
It is strongly alkaline, flammable, volatile, mixes with water and ethanol, colourless liquid (if pure), strong unpleasant odour, combustion forms dangerous nitrogen gases.
Diethylamine, Solution <2%, Not hazardous.

Dihydrosanguinarine, (C20H15NO4), Isoquinoline Alkaloid
Dihydrosanguinarine, Dihydroavicine, benzophenanthridine alkaloid, dihydroavicine, benzophenanthrodine, antifungal agent, antiseptic, anti-inflammatory.
It occurs in Fumaria, Corydalis, Eschscholzia, Pteridophyllum, in arcocapnos baetica and in Sarcocapnos saetabensis
See diagram: Dihydrosanguinarine.

Dioscorine, (C13H19NO2), Pyrrolidine and Piperidine Alkaloid
Dioscorine, opalescent (yellow-red to blue), molecule, contains a non-aromatic pyran ring, neurotoxin, convulsant, arrow poison.
It occurs in Yam Dioscorea hispids, in Dioscorea dregeana, in Dioscorea bulbifera
See diagram: Dioscorine.