Edexcel IGCSE Chemistry - Paper 1

Potassium manganate (VII) and water (purple colour spreads), ammonia and hydrogen chloride (white ring forms closer to hydrogen chloride), bromine gas and air (brown bromine gas diffuses)

3 experiments to show diffusion

4OH- = O2 + 2H2O + 4E-

Half equation for hydroxide ions

Moves slowly (on the surface), fizzes, eventually disappears

Lithium with water - observations

Moves quickly (on the surface), fizzes rapidly, may ignite

Sodium with water - observations

Reacts vigorously, burns with a lilac flame, sometimes explodes

Potassium with water - observations

Heat copper (in a tube and pass air over it)

Experiment to test the proportion of oxygen in air

Pale blue

Sulfur flame colour

Orange/yellow

Carbon flame colour

Downward delivery (it is denser than air)

How to collect chlorine

2H2O + CaCO3 = CaCl2 + H2O + CO2

How to make CO2 in a lab (equation)

It is soluble in water

Why can CO2 be used in fizzy drinks?

Platinum wire, dip in hydrochloric acid, hold in flame

Flame test wire to use + how to sterilise it

So the gas can dissolve and make the colour change

Why does litmus paper need to be damp when testing a gas?

Hydrochloric acid

Acid added to remove any impurities for the sulphate test

Nitric acid

Acid added to remove any impurities for the halide test

Bleaches damp litmus paper white

Test for chlorine

A group of organic compounds that can all be represented by the same general formula

Homologous series

Similar chemical properties, a trend in physical properties (boiling points, colour, viscosity)

Members of the same homologous series have...

A group of atoms which are arranged or bonded in a particular way and which determine how an organic compound will react

Functional group

Carbon to hydrogen bond

Alkane functional group

Carbon double bond

Alkene functional group

Hydroxide bond

Alcohol functional group

Carbon

An organic compound is one that contains

CnH2n+2

Alkane general formula

CnH2n

Alkene general formula

CnH2n+1OH

Alcohol general formula

Meth (1), eth (2), prop (3), but (4), pent (5)

First 5 names of the organic compounds

Compounds ONLY containing hydrogen and carbon

Hydrocarbons

UV light

What condition is needed for halogens to react with alkanes?

Turn orange bromine water to colourless

Test for alkenes

They can make more bonds (their double bond can 'open up')

Why are alkenes unsaturated?

0-14

pH scale

Neutralisation

Acid + base = salt + water - what type of reaction is this?

Salt + water

Acid + metal oxide =

Salt + water + carbon dioxide

Acid + metal carbonate =

Precipitation reaction

How do you make an insoluble salt?

Only works with solutions that are initially colourless, subjective

2 disadvantages of measuring the rate of reaction by timing how long it takes for a precipitate to form

Releases potentially harmful gas into the room

A disadvantage of measuring the rate of reaction by measuring the change in mass

Most accurate (as mass balances are very accurate)

An advantage of measuring the rate of reaction by measuring the change in mass

If the reaction is too vigorous the plunger might blow out the end of the syringe

A disadvantage of measuring the rate of reaction by measuring the volume of gas given off

Quite accurate

An advantage of measuring the rate of reaction by measuring the volume of gas produced

Hydrochloric acid + marble chips

Experiment to show the effect of surface area on the rate of reaction

Magnesium + hydrochloric acid

Experiment to show the effect of concentration on the rate of reaction

Sodium thiosulfate + hydrochloric acid (produces a cloudy precipitate)

Experiment to show the effect of temperature on the rate of reaction

Decomposition of hydrogen peroxide (catalyst = manganese (IV) oxide)

Experiment to show the effect of a catalyst on the rate of reaction

The particles have more area to work on, so the frequency of collisions with greater the activation energy will increase

How a larger surface area increases the rate of reaction

It gives the particles a surface to stick to which increases the frequency of successful collisions by providing an alternative reaction pathway with a lower activation energy

How a catalyst increases the rate of reaction

Polystyrene cup, cotton wool, lid, thermometer

Calorimetry experiment for dissolving, displacement or neutralisation reactions (4 pieces of equipment)

Spirit burner, water, draught excluder, thermometer, lid

Calorimetry experiment for combustion (5 pieces of equipment)

Electrolysis

How to extract elements more reactive than carbon (potassium, sodium, calcium, magnesium, aluminium)

Zinc, iron, lead

3 metals extracted by heating with carbon

Decomposition by heating alone, followed by electrolysis

How is copper extracted?

Lowers the melting point of aluminium oxide (from 2000 degrees celsius to 900 degrees celsius)

Role of cryolite in the extraction of aluminium

Al3+ + 3e- = Al

Half equation at the cathode for aluminium extraction

2O2- = O2 + 4e-

Half equation at the anode for aluminium extraction

C + O2 = CO2

Reaction 1 in extracting iron

C + CO2 = 2CO

Reaction 2 in extracting iron

3CO + Fe2O3 = 3CO2 + 2Fe

Reaction 3 in extracting iron

CaCO3 = CaO + CO2

Reaction 4 in extracting iron

CaO + SiO2 = CaSiO3

Reaction 5 in extracting iron

Road building, fertiliser

2 uses of slag

Railings, malleable

Wrought iron use (almost pure iron) + property that allows it to be used for this

Manhole covers, hard (but brittle)

Cast iron use (iron, carbon and silicon) + property that allows it to be used for this

Car bodies (and girders), malleable (+ harder than pure iron)

Steel use (iron and carbon) + property that allows it to be used for this

Cutlery, doesn't corrode

Stainless steel use (iron and chromium) + property that allows it to be used for this

Strong, low density

Why is aluminium used for making aircraft bodies?

Doesn't corrode

Why is aluminium used for making food containers?

Good conductor, low density

Why is aluminium used for making overhead cables?

Bottled gas (for heating)

Refinery gases use

Chemicals (plastics, dyes, drugs, explosives, paints)

Naphtha use

Jet fuel

Kerosene use

Road surfacing

Bitumen use

Stop separated liquids from running back down the column and remixing

Role of bubble caps in the fractionating column

How readily a substance evaporates at normal temperatures (and pressures)

Volatility

High pressure

What condition is needed for an addition polymer to be made?

Packaging (plastic bags, bottles), light and stretchable

Poly(ethene) use + properties that mean it can do this

Kettles, tough, flexible, resistant to heat

Poly(propene) use + properties that mean it can do this

They are inert

Why aren't polymers biodegradable?

To make nitric acid

What is ammonia used for in the ostwald process?

It has nitrogen from two sources (ammonia and nitric acid and plants need nitrogen to make proteins)

Why is ammonium nitrate such a good fertiliser?

Repeat the experiment (at least 3 times)

How do you improve reliability?