AQA Chemistry Paper 2 Review

Flashcards for AQA Chemistry Paper 2 review, covering topics 6 to 10: rates, organic analysis, atmospheric chemistry, and resources.

Rate of reaction

How quickly a reaction happens.

Rate

Change in a quantity divided by time; in the context of reaction rates, it's the amount of reactant used or product formed over time.

Increased turbidity

An increase in the cloudiness of a solution.

Gas Production Graph

A graph showing the quantity of product on the y-axis and time on the x-axis.

Tangent

A line drawn at a specific point on a curve to determine the rate of reaction at that time.

Factors that increase reaction rate

Increasing the concentration of reactants, increasing the pressure of gas reactants, and increasing the surface area of solid reactants.

Catalyst

A substance that increases the rate of a reaction without being used up in the reaction itself.

Reversible reactions

Reactions where the products can revert back to the original reactants.

Equilibrium

A state where the rates of the forward and reverse reactions are equal, resulting in no overall change in the quantities of reactants and products.

Le Chatelier's principle

If a system at equilibrium is subjected to a change, the system will adjust to counteract that change.

Organic compounds

Compounds that have carbon forming the backbone of the molecules.

Crude oil

A mixture of different length alkanes.

Alkanes

Chains of single covalently bonded carbon atoms surrounded by hydrogen atoms.

General formula for alkanes

CnH2n + 2

Fractional distillation

A process used to separate crude oil into different fractions based on boiling points.

Boiling point of Alkanes

Longer alkanes have higher boiling points because there are stronger intermolecular forces between them, which means more energy is needed to overcome them.

LPG

liquid petroleum gas contains a range of chain length alkanes up to four carbons long.

Flammability of Alkanes

Shorter fractions are more flammable and easy to burn.

Alkene

A hydrocarbon that has a carbon-carbon double bond.

Alkene test

A colorless liquid that turns colorless when bromine water is added.

Cracking

Breaking apart a longer alkane into a shorter alkane and an alkene.

Catalytic cracking

Requires a temperature of around 550°C and a catalyst called a zeolite.

Steam cracking

Uses an even higher temperature of over 800°C without a catalyst.

Alcohol

It's an organic compound with an -OH functional group.

Alcohol reaction with oxygen

Can react with oxygen—that is, combust—to make carbon dioxide and water if it's complete combustion, and carbon monoxide or carbon and water if it's incomplete combustion when there's less oxygen available.

Carboxylic acid

A molecule with, instead of -OH, it's -COOH; that's the functional group.

Polymers

Super long-chain alkanes made up of repeating sections made from monomers.

Poly vs Mono

Lots; mono just means one.

Condensation polymerization

When we join together two monomers that have two functional groups.

Amino acids

Have two functional groups: an amino group -NH2 and a carboxy group -COOH.

Formulation

A mixture that has been specially designed to be useful in a very specific way, with very specific quantities of different substances.

Chromatography

A way of separating substances in a mixture.

RF value

A ratio of how far a spot has moved compared to the solvent.

Hydrogen test

Will produce a squeaky pop.

Oxygen test

Will relight a glowing splint.

Carbon dioxide test

Will turn lime water cloudy when bubbled through it.

Chlorine gas test

Will bleach damp blue litmus paper—that means turn it white.

Carbonate Test

Carbonates react with acids to make carbon dioxide gas.

Halide ions test

Mixed with silver nitrate solution and nitric acid.

Sulfate ions test

Will produce a white precipitate when mixed with barium chloride and hydrochloric acid.

Greenhouse effect

Water vapor, carbon dioxide, and methane absorb longer wavelength radiation and keep the Earth warm.

Carbon monoxide

An atmospheric pollutant; it binds to your red blood cells, so less oxygen can be transported around your body.

Carbon footprint

A term that's the idea that everything you do is responsible for carbon dioxide being released into the atmosphere and that we should reduce that or offset it by planting trees, for example.

Potable water

Have low enough levels of salt and microbes that it's safe to drink.

Sludge

the solid stuff that sinks to the bottom, which needs anaerobic digestion to treat, whereas the liquid effluent from the top requires treatment with aerobic respiration.

Phytomining

Uses the fact that plants absorb minerals from the soil into their roots

Bioleaching

Uses bacteria that make leachates—solutions that contain metal compounds—and we can get the metal from those.

LCA

The thought process carried out in order to predict a new product's impact on the environment.

Corrosion

When materials are destroyed slowly over time by chemical reactions.

Alloys

Mixtures of different metals.

the Haber process

Used to make ammonia, which can be used for fertilizers.

Plants fertilizer requirements

Need nitrogen to grow, which is why we use ammonium in fertilizers, but they also need phosphorus and potassium.