CHEMISTRY IGCSE 🚨🚨🚨

Test for hydrogen

Lit splint creates squeaky pop

Test for oxygen

Glowing splinter relights

Test for Carbon dioxide

Bubbled through limewater, turns milky/cloudy

Test for chlorine

Damp litmus is bleached

Test for ammonia

Glass rod dipped in hydrochloric acid, put this in test tube

White smoke of ammonium chloride is observed

Flame test - lithium

Red

Sodium flame test

Yellow

Potassium flame test

Lilac

Calcium flame test

Orange -red

Copper flame test

Blue-green

Identify a strongly acidic substance

Hydrochloric acid

Identify and weakly acidic substance

Ethanoic acid

Identify a neutral solution

Water, sodium chloride

Identify a Weakly alkaline solution

Ammonia

Identify a strongly alkaline solution

Sodium hydroxide

Litmus is

Red in acids, blue in alkalis

Methyl orange

Red in acids, yellow in alkalis

Phenolphthalein Is

Colourless in acids, pink in alkalis

Universal indicator is

Red in acids, blue in alkalis

Metal + acid —>

Salt + hydrogen

Metal carbonate + acid —>

Salt + water +carbon dioxide

Metal oxide/hydroxide + acid —>

Salt + water

Test for halide anions

Dilute nitric acid , them silver nitrate

Chloride

White precipitate —silver chloride

Bromide , Br-

Cream precipitate— silver bromidde

Iodide, I-

Yellow precipitate — silver iodide

Test for ammonium

Add sodium hydroxide and warm mixture

Test for gas with DAMP RED LITMUS PAPER TURNS BLUE

Test for sulfates

Add hydrochloric acid

Add barium chloride —> white precipitate is formed

Test for carbonates

Add dilute hydrochloric acid —> fizzing (effervescence) occurs

Test fo r presence of water

Anhydrous copper sulfate turns blue

Calcium cation test

White precipitate

Iron (II), cation test Fe2+

Green ppt

Iron (III) cation test fe3+

Brown

Aluminum cation test Al3+

Colourless

Exothermic

Reactants are losing heat

Appears hotter

Endothermic reactions

Absorb heat from the surroundings

How to calculate heat change

Q = mcdeltat

Bond breaking…

…needs energy -endothermic

Bond making…

…releases energy — exothermic

The specific heat capacity of water

4.18/J/g/°c

Hydrocarbons

Molecules that contain carbon and hydrogen only

Saturated compunds

Compounds that only single C-C bonds

Unsaturated compounds

Containing double or triple C-C bonds

Reactions of alkanes with alkane sin the presence of UV

Halogen + alkane —> halogenoalkane + hydrogen halide

Why not sulfuric acid for carbonate test

Will form insoluble layer of calcium sulfate around calcium carbonate, which stops the reaction

Crude oil

Mixture of hydrocarbons

How is crude oil separated

Fractional distillation

Fractions of crude oil

Refinery gases

Petrol (Gasoline)

Kerosene

Diesel

Heavy fuel oil

Bitumen

Refinery gas uses

Domestic cooking; LPG

Gasoline/petrol

Car fuel

Kerosene

Jet fuel

Diesel

Diesel engines

Fuel oil

Fuel for ships

Bitumen

Surfacing roads

Appropriate temperature for cracking

600-700°c

Properties of group 1

• soft

• Low densities

• Very reactive

• Form alkaline solutions when reacting with water

Eee\

Reactivity down group 1

Increases

Group 7 properties

• non-metals

• Poisonous

• Diatomic

Homogulous series

A series of compounds that have similar chemical properties because they have the same functional group

Functional group

A group of atoms responsible for thhe chemical reactions of a compound

Isomerism

Compounds with the same molecular formula but different displayed formula

Electrical conductivity of covalent compounds

Most covalent compounds do to conduct at all

Simple molecular structures are poor conductors

“Give the name of the black substance that forms on the bottom of the container ”

Carbon

Hydration of ethene

• react ethene with steam

What catalyst is used in hydration of ethene

Phosphoric acid

Temp and pressure in hydration of ethene

60-70atm

300 degrees

Fermentation of glucose

• Yeats is added to sugar/starch solution

• Left at 30 degrees in absence of oxygen

• Enzymes denature if >40 degrees

What enzymes are used in fermentation

Zymase

Batch process v continuous process

• batch process is slower

• Batch process used renewable resources

• Continuous process produces purer ethanol

Characteristics of a homologous series

M1 each member differs from the next by a CH2 group OWTTE

M2 (each member has) same functional group

M3 (each member has) similar/same chemical properties / similar/same (chemical) reactions

M4 trend in physical properties (between successive members)