Chemistry Experiments, D¶

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.

DEHP¶

DEHP, C₂₄H₃₈O₄, di-(2-ethylhexyl)phthalate, is a polyvinyl chloride resin plasticiser. source

Deidaclin¶

Deidaclin, C₁₂H₁₇NO₆, cyanogenic glycoside, occurs in (Tetrapathaea tetrandra), (Kiggelaria africana), and (Passiflora foetida). source

Demineralized water¶

Demineralized water, "demi water", minerals or salts removed, is used to replace expensive distilled water.

Depression¶

Freezing point depression and boiling point elevation: 24.4.1

Freezing point depression of carbonated water, cola: 24.4.3

Diazepam¶

Diazepam, C₁₆H₁₃ClN₂O, (Valium), 1,4-benzodiazepinone, white-yellow crystalline powder, is almost odourless, tasteless then bitter aftertaste. source

It is an anti-anxiety drug, anticonvulsant, sedative, and it has a low potential for drug abuse.

Dibutyl phthalate¶

Dibutyl phthalate, C₁₆H₂₂O₄, DPB, is a plasticiser, food contaminant, colourless, oily liquid, with a weak odour. source

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, was once used widely, but is now banned for plant protection product in the EU. source

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. source

It occurs in woolly foxglove (Digitalis lanata).

Digitalis lanata was used to treat heart conditions, but it comes with severe side effects.

The plant is poisonous in all parts and is a declared weed in many countries.

Dihydrocubebin¶

Dihydrocubebin, C₂₀H₂₂O₆, glycol, lignan, butanediol, benzodioxole, is a antimicrobial. source

It occurs in (Podolepis rugata), (Horsfieldia irya) bark, leaves, and wood.

Dihydrokarvain¶

Dihydrokarvain, C₁₄H₁₆O₃, kavalactone, anxiolytic. source

It occurs in kava, (Piper methystichum).

Dihydromethysticin¶

Dihydromethysticin, C₁₅H₁₆O₅, 2-pyranone, quinone, aromatic ether, spasmolytic source

It occurs in (Piper methysticum), (Piper majusculum), and in (Aniba hostmanniana).

D-Glucose¶

Danielone¶

Danielone, C₁₀H₁₂O₅, an acetophenone, aromatic ketone, phytoalexin, antifungal activity source

It occurs in Papaya species fruit, (Cestrum parqui), and in (Euglena gracilis).

Dantron¶

Dantron, C₁₄H₈O₄, chrysazin, (1,8-dihydroxyanthraquinone), health hazard, former laxative source

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¶

Darmstadtium, Ds ( German Darmstadt, where it was first produced in Germany), radioactive transuranic element.

Darmstadtium, Table of the Elements

Darmstadtium, RSC

Decomposition¶

12.2.2 Decomposition reactions

Decomposition of water

15.5.4 Electrolysis of water

12.11.3.4 Tests for substances, sublimation, melting, decrepitation

3.7.0 Thermal decomposition, List

DEET¶

DEET, C₁₂H₁₇NO, N,N-Diethyl-meta-toluamide, diethyltoluamide, "PESTANAL", common in pesticides source

It gives short-term protection against Anopheles species mosquitoes, rather than Culicine mosquitoes.

See diagram16.13.8chd: DEET, diethyltoluamide

Deliquescent¶

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), source

Potassium iodide. KI, (slight), Sodium nitrate NaNO₃, (if in moist air), Sodium thiosulfate Na₂S₂O₃.5H₂O, (if in moist air) source

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, C₁₅H₁₁O₇⁺, anthocyanin, hexahydroxyflavylium, antineoplastic, blue pigment source

It occurs in Viola species, Delphinium species, grape (Vitis vinifera), and cranberry Vaccinium.

Delphinidin 3-O-glucoside, C₂₁H₂₁O₁₂ source

Delphinidin chloride, C₁₅H₁₁ClO₇, pigment, occurs in grape, cranberry, and in pomegranate. source

Delsoline¶

Delsoline, C₂₅H₄₁NO₇, acomonine, is a diterpenoid, and may cause convulsions and respiratory depression. source

It occurs in (Delphinium consolida), and in (Aconitum monticola).

Demethyldeoxypodophyllotoxin¶

Demethyldeoxypodophyllotoxin, C₂₁H₂₀O₇, is a lignan, gamma-lactone, a phenol, immunosuppressive, antioxidant, antineoplastic, antileukemic. source

It occurs in roots of (Polygala paena), and in (Hyptis verticillata).

Demethoxypiplartine¶

Demethoxypiplartine, C₁₆H₁₇NO₄, (3'-Demethoxypiplartine), is a phenylpropanoid. source

Demethoxypiplartine has benused to traet diseases caused by the fungus (Cryptococcus neoformans). It occurs in (Piper tubercalatum) and other Piper species.

Deoxykaempferol¶

Deoxykaempferol, C₁₅H₁₀O₅, (3,7,4'-Trihydroxyflavone), has a chemopreventive effect on UVB-induced skin carcinogenesis. source

It occurs in chickpea (Cicer arietinum).

Desacetoxymatricarin¶

Desacetoxymatricarin, C₁₅H₁₈O₃, leukomisin, is a CoA reductase inhibitor, and a highly anti-hypercholesterolemic sesquiterpene lactone. source

It is contained in "Oligvon", which is used to prevent and treat artherosclerosis.

It occurs in (Artemisia princeps) and its derivatives occur in Achillea.

Detergents¶

Detergent, SYNDET, Synthetic Detergent: 7.4.19

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)- source

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, 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, (C₆H₁₀O₅)n source

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: 16.3.3

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 source

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

Dichlorodifluoromethane, CCl₂F₂ source

(2,4-D), (2,4-dichlorophenoxyacetic acid): 4.4.1 (Weedicide))

Dichlorobenzene¶

1,2-dichlorobenzene, o-dichlorobenzene, toxic, avoid inhalation of vapour

1,2-dichlorobenzene. Solution < 5% Not hazardous

1,4-Dichlorobenzene, C₆H₄Cl₂, MP. 53 oC , crystalline, p-DCB, para-dichlorobenzene, 1,4-dichlorobenzol, toxic if ingested, colourless strong odour source

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.)

Dichloroacetic acid¶

Dichloroacetic acid, dichloroethanoic acid, DCA, CHCl₂COOH, toxic by all routes, Vapour irritates lungs source

Dichloroacetic acid, Solution < 1%, Not hazardous (in chlorinated drinking water)

Dichlorobiphenyl¶

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

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¶

Dichloromethane, CH₂Cl₂, methylene chloride, methylene dichloride, Freon 30, toxic by all routes, possibly carcinogenic source

Dichloromethane, Solution < 1%, Not hazardous

Colourless liquid, BP 41 oC, (refrigerant, degreasing, cleaning fluid, paint strippers, solvent), ozone-depleting chemical so use very small amounts.

Instead use ethanol as solvent for dilute solutions.

Organic solvent, in paint strippers, low BP of 39.6 oC .

1.0 Poisons, First Aid, (See: Dichloromethane, CH₂Cl₂) source

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.)

DCPIP¶

DCPIP, C₁₂H₇NCl₂O₂, dichlorophenolindophenol, dichloro-indophenol, dichlorophenol solution, tablets, toxic source

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)

DDT, C14H9Cl5¶

DDT, C₁₄H₉Cl₅ source

DDT, insecticide, New IUPAC name: 1,1'-(2,2,2-Trichloroethane-1,1-diyl)bis(4-chlorobenzene)

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

Decarboxylation¶

Decarboxylation, removing carboxyl group from compound

Deci¶

deci, one tenth, e.g. decilitre = 1/10 litre

Diamino¶

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

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, source

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 source

Diaminobutyric acid¶

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

Diaminohexane¶

Diaminohexane, C₆H₁₆N₂, H₂N(CH₂)₆NH₂, (1,6-hexanediamine), HMDA, hexamine, methenamine, urotropine source

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 source

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)

Filters (Swimming pools): 18.4.7

Nitroglycerine (UK), Nitroglycerin (USA): 16.6.10

Dichlorodifluoromethane¶

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

Dichromates¶

Dichromate ion Cr₂O₇₂^- source

Dichromates, ( - Cr₂O₇^-), strong oxidizing agents, e.g. potassium dichromate K₂Cr₂O₇, are usually orange-red salts. source

Sodium dichromate, red-orange crystals, SG 2.35, is soluble in water.

Sodium dichromate, is insoluble in alcohol, if heated to decomposition, emits toxic fumes of sodium monoxide.

Chromic acid, ionization reaction, H₂CrO₄: source

H₂CrO₄ + H₂O → H₃O⁺ + HCrO₄^-, K1 = 2 × 10-1 source

HCrO₄^- + H₂O → H₃O⁺ + CrO₄₂^-, K2 = 3.2 × 10-7 source

Chromates, dichromates, hazards: 3.7.4

Chromic acid, Ionization reactions: 12.8.7

Oxidize chromium compounds to chromates: 12.8.5

Potassium dichromate

Reactions of 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, -(C2H5)2

Diethyl ketone, pentan-3-one

Diethyl sulfate, toxic by all routes, Not permitted in schools

Diethylamine

Diethylaminopropylene, DMAPA, curing agent for epoxy resin adhesive, surface coating, irritant

Diethyl ether

Diethylphenylenediamine, C₁₀H₁₆N₂ source

Diethylene glycol, C₄H₁₀O₃, DEG (cosmetics, photography developer), toxic source

Diethylenetriamine, C₄H₁₃N₃, NH₂CH₂(CH₂)₂NH, DTA, tridentate ligand, curing agent for epoxy resin adhesive, surface coating, Irritant source

Diethyl ether¶

Diethyl ether, C₄H₁₀O, ethoxyethane, ethyl oxide, ethyl ether, sulfuric ether, anaesthetic "ether", toxic by all routes, Not permitted in schools source

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 source

N,N-diethyl-p-phenylenediamine, Solution < 3%, Not hazardous

Digiferrugineal¶

Digiferrugineal, Digiferruginol, C₁₅H₁₆O₅, an anthraquinone, cytotoxic to human nasopharynx carcinoma, phytoalexin, antimicrobial. source

It occurs in Streptocarpus, Digitalis, (Morinda parvifolia), and in Cinchona.

Dihydrocaffeic acid¶

Dihydrocaffeic acid, C₉H₁₀O₄, 3,4-Dihydroxyhydrocinnamic acid, hydrocaffeic acid, a monocarboxylic acid, antioxidant source

It occurs in normal human biofluids, improves platelet function, in human plasma after coffee ingestion, and in artichoke leaf extract

Dihydroxyacetone¶

Dihydroxyacetone, C₃H₆O₃, 1,3-Dihydroxy-2-propanone, irritant, a ketotriose, a primary alpha-hydroxy ketone, antifungal agent source

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 source

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 source

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

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 source

It occurs in cereals and cereal products.

It is an insecticide and fungicide.

Dimethyl sulfate¶

Dimethyl sulfate (DMS), (CH3O)2SO2, (CH3)2SO4, diester of methanol and sulfuric acid

Dimethylamine¶

Dimethylamine, (CH3)2NH or C₂H₇N, N-Methylmethanamin, secondary aliphatic amine, liquefied and flammable colourless gas source

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 source

Dimethyl aminoazobenzene-4-sulfonate, C₁₂H₁₁N₃, 4-aminoazobenzene, aniline yellow, orange powder, salts used for azo dyes source

Dimethyl aniline, C₈H₁₁N, (CH3)2C6H3NH2, C₆H₅N(CH₃)₂, (4-dimethylaniline) source

Dimethyl benzene C₆H₄(CH₃)₂, C₈H₁₀, one of 3 isomers is Xylene, 1,3-Dimethylbenzene source

Dimethyl disulfide, C₂H₆S₂, DMDS, volatile, offensive garlic-like odour in bad breath, in municipal solid waste landfill source

Dimethyl formamide C₃H₇NO or HCON(CH₃)₂, DMF, (N,N,dimethylformamide), solvent, paint thinner, odourless, but fish smell if impure source

Dimethyl polysiloxane (C₂H₆OSi)n, polydimethylsiloxane, PDMS, food additive E900 source

Dimethyl sulfate, C₂H₆O₄S, corrosive, oily, onion-like odour, heat fumes, toxic by all routes, Not permitted in schools source

Dimethyl sulfide, C₂H₆S, DMS, methylthiomethane, volatile, inflammable, offensive sweet smell, in flatus and smell of the sea source

Dimethyl sulfoxide, C₂H₆OS, (CH3)2SO), DMSO: 16.10.12 source

Dimethyl trisulfide, DMTS, CH₃SSSCH₃, volatile, bad odour from cooked Brassicaceae vegetables, boiled cabbage smell source

Diosmetin¶

Diosmetin, C₁₆H₁₂O₆, Flavonol, (4'-methyl ether), Salinigricoflavonol, trihydroxyflavone source

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 so use very small amounts source

Dioxane, Solution < 1%, Not hazardous

Diphosphane¶

Diphosphane, P₂H₄ (formerly diphosphine), very toxic, as impurity causes phosphine to ignite in air. source

Phosphine, PH₃ source

Fluorophores: 14.26

Disodium orthophosphate¶

Disodium orthophosphate, disodium hydrogen phosphate, Na₂HPO₄, sodium phosphate dibasic, disodium phosphate, sodium hydrogen phosphate source

It has white monoclinic or rhombic crystals or granules, RD. 1.5, MP. 34 to 35 oC , easily loses H₂O, E339. source

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)

Diterpenoids¶

Ajugarin I, C₂₄H₃₄O₇, diterpenoid, insect antifeedant, has anti-neuropathic pain activity, and occurs in leaves of (Ajuga remota). source

Andrographolide, C₂₀H₃₀O₅, diterpenoid, bitter taste, anti-inflammatory, antioxidant, anti-cancer source

It is used in many traditional medicines to treat infectious diseases and cardiovascular poblems.

It occurs in (Andrographis paniculata).

Candletoxin A, C₃₅H₄₄O₉, a diterpenoid, toxic, in (Euphorbia poisonii) latex. source

Caryoptin, C₂₆H₃₆O₉, diterpenoid, bitter, insect antifeedant, in Caryopteris. source

Casbene, C₂₀H₃₂, diterpene, antifungal agent, in castor oil Ricinus communis. source

Geranylgeraniol, C₂₀H₃₄O, diterpenoid, in linseed oil Linum usitatissum, in wood oil Australian red cedar Toona ciliata. source

Gibberellin, (Gibberellin A3, GA, GA3, Gibberellic acid), Gibberellin, Gibreskol, C₁₉H₂₂O₆ pentacyclic diterpenoid, irritant, a C19-gibberellin. source

monocarboxylic acid, white powder, potent plant hormone that regulates growth and cell elongation, stimulates cells of germinating seeds.

Ginkgolide, Ginkgolide A, C₂₀H₂₄O₉, diterpenoid, irritant, bitter, Platelet Activating Factor antagonist, bronchdilator, anti-asthmatic source

It occurs in (Ginkgo biloba) root bark and leaves.

Gnidicin, Thymeleatoxin A, C₃₆H₃₆O₁₀, diterpenoid, anti-tumour, in Gnidia. source

Grayanotoxin(GI), Rhodotoxin, Asebotoxin, Acetylandromedol, C₂₂H₃₆O₇, tetracyclic diterpenoid, acetate ester, phytotoxin, antihypertensive. source

It occurs in Rhododendron and its honey, Kalmia, Leucothoe.

Labdane, C₂₀H₃₂O₂, antifungal diterpenoid, and occurs in (Nicotiana glutinosa) epicuticle leaf wax. source

Mascaroside, C₂₀H₃₆O₁₁, diterpenoid, naphthofuran, very bitter, in Coffea viyanneya beans. source

NeocembreneNeocembrene A, Cembrene A, C₂₀H₃₂, diterpene, macrocycle, occurs in Picea obovata. source

Palmarin, Tinosporide, Arcangelisin, Isochasmanthin, C₂₀H₂₂O₇, diterpenoid, organo-oxygen compound, organic heterotricyclic compound, bitter. source

It was used in Radix columba tonic, in Jateorhiza roots.

Phorbol, C₂₀H₂₈O₆, is a tetracyclic diterpenoid, acute toxic, cyclic ketone, a tertiary alcohol, an acyclic diterpene alcohol, white solid, irritant phorbol. source

Phorbol diesters may be anti-leukaemic and carcinogenic, occurs in (Croton tiglium) seed oil.

Phytol, trans-Phytol, (20H₄₀O), diterpenoid, acyclic diterpene alcohol, irritant, environmental hazard, used to prepare vitamin E and vitamin K1, modulates transcription in cells, long-chain primary fatty alcohol, oily liquid, modulates transcription in cells, schistosomicide, decomposition product of chlorophyll. source

Dithizone¶

DithizoneH, C₁₃H₁₂N₄S, C₆H₅NHNHCSN=N(C6H5), dithiozone, dithizon, diphenyl thiocarbazone, phenylhydrazine. source

It is a 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 source

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), source

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 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

Tetraterpenoids, (C₄₀H₆₄) source

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, Db

Dubnium, Table of the Elements.

Dubnium, RSC

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

Deuterium, 2H¶

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. source

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, 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

Desiccants

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 source

Concentrated sulfuric acid removes water from the white to colourless sucrose molecules to leave black carbon.

C₁₂H₂₂O₁₁ → 12C + 11H₂O source

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.

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, (C₁₃H₁₇NO₂), Tropane Alkaloid source

Darlingine, oxacycle.

It occurs in (Darlingea ferruginea).

Delcosine, (C24H39NO7), Diterpenoid Alkaloid¶

Delcosine, (C₂₄H₃₉NO₇), Diterpenoid Alkaloid source

Delcosine, Delphamine, Lucaconine, Delcosin, Iliensine, poisonous, insecticidal.

It occurs in Aconitum. and in (Delphinium consolida).

Delphinine, (C33H45NO9), Diterpenoid Alkaloid¶

Delphinine, (C₃₃H₄₅NO₉), Diterpenoid Alkaloid source

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.

Deltaline, (C27H41NO8), Diterpenoid Alkaloid¶

Deltaline, (C₂₇H₄₁NO₈), Diterpenoid Alkaloid source

Deltaline, Delphelatine, eldeline, tertiary alcohol, tertiary amino compound, acetate ester, cyclic acetal, organic polycyclic compound

It occurs in (Delphinium cheilanthum) and in (Delphinium andersonii), Ranunculaceae.

Demecolcine, (C21H25NO5), Colchicine Alkaloid¶

Demecolcine, (C₂₁H₂₅NO₅), Colchicine Alkaloid source

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 in (Colchicum arenarium), Colchicaceae.

Demethylcoclaurine, (C16H17NO3), Isoquinoline Alkaloid¶

Demethylcoclaurine, (C₁₆H₁₇NO₃), Isoquinoline Alkaloid source

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 Isoquin8: Demethylcoclaurine

Dendrobine, (C16H25NO2), Monoterpenoid and Sesquiterpenoid Alkaloid¶

Dendrobine, (C₁₆H₂₅NO₂), Monoterpenoid and Sesquiterpenoid Alkaloid source

Dendrobine, occurs in Dendrobium species, antiviral, antitumour, lowers blood pressure,and may cause death by convulsions.

Denudatine, (C22H33NO2), Diterpenoid Alkaloid¶

Denudatine, (C₂₂H₃₃NO₂), Diterpenoid Alkaloid source

Denudatine, acute toxic, effects on action potential of ventricular fibres, inhibits arrhythmogenic action of aconitine

It occurs in Delphinium.

Deserpidine, (C32H38N2O8), Indole Alkaloid¶

Deserpidine, (C₃₂H₃₈N₂O₈), Indole Alkaloid source

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).

Diethanolamine, Secondary Amine¶

Diethanolamine, Secondary Amine

Diethanolamine, [HN(CH₂CH₂OH)₂], DEA, secondary amine (also "dialcohol", because two OH groups), weak base, oily colourless liquid or white crystals source

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), Secondary Amine source

Diethylamine, [C₄H₁₁N(C₂H₅)₂NH], (CH₃-CH₂-NH-CH₂-CH₃), diethyl amine, Toxic by all routes, Irritant to eyes, corrosive to eyes and skin source

It is strongly alkaline, flammable, volatile, mixes with water and ethanol, colourless liquid (if pure), strong unpleasant odour, combustion forms dangerous nitrogen oxides

Diethylamine, Solution <2%, Not hazardous.

Dihydrosanguinarine, (C20H15NO4), Isoquinoline Alkaloid¶

Dihydrosanguinarine, (C₂₀H₁₅NO₄), Isoquinoline Alkaloid source

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 Isoquin3: Dihydrosanguinarine

Dioscorine, (C13H19NO2), Pyrrolidine and Piperidine Alkaloid¶

Dioscorine, (C₁₃H₁₉NO₂), Pyrrolidine and Piperidine Alkaloid source

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), and in (Dioscorea bulbifera).

Digitogenin, C27H44O5, a sapogenin, a 2alpha-hydroxy steroid¶

Digitogenin, C₂₇H₄₄O₅, a sapogenin, a 2alpha-hydroxy steroid source

It occurs in (Digitalis lanata).

Digitonin, Digitin, C56H92O29, a steroid saponin, toxic, it solubilizes lipids, and is a glycoside.¶

Digitonin, Digitin, C₅₆H₉₂O₂₉, a steroid saponin, toxic, it solubilizes lipids, and is a glycoside. source

It occurs in (Digitalis purpurea).

Diosgenin, C27H42O3, a steroid sapogenin, nitogenin, a hexacyclic triterpenoid¶

Diosgenin, C₂₇H₄₂O₃, a steroid sapogenin, nitogenin, a hexacyclic triterpenoid source

It occurs in bark of wild yam, (Discorea villosa

It is used to synthesise steroids, e.g. cortisone, pregnenolone and progesterone, and is an apoptosis inducer, antiviral, antineoplastic.

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