GCSE Chemistry Study guides, Class notes & Summaries

This is the final mark scheme

What is the rate of reaction? - Answer How fast reactants turn into products What is reaction rate important in? - Answer The chemical industry and your body Why is reaction rate important in the chemical industry? - Answer To make sure products are made quickly and cheaply What are the two ways you can work out the rate of a chemical reaction? - Answer How quickly the reactants are used up and how quickly the products are made What are the three techniques you can use to get...

What is the rate of reaction? - Answer How fast reactants turn into products What is reaction rate important in? - Answer The chemical industry and your body Why is reaction rate important in the chemical industry? - Answer To make sure products are made quickly and cheaply What are the two ways you can work out the rate of a chemical reaction? - Answer How quickly the reactants are used up and how quickly the products are made What are the three techniques you can use to get...

What is the % of nitrogen in our current atmosphere? - Answer 80 What is the % of oxygen in our current atmosphere? - Answer 20 What is the % of carbon dioxide in our current atmosphere? - Answer 0.04 What is the % of argon in our current atmosphere? - Answer 0.9 Describe how the early atmosphere was formed? - Answer Frequent volcanic eruptions released gases Name the main gases in the early atmosphere? - Answer Carbon dioxide, methane, ammonia and water vapour Expl...

what is rate of reaction - Answer how fast the reactants are changed into products example of slow reaction - Answer rusting of metal example of fast reaction - Answer explosion how does temp affect rate of reaction - Answer the higher the temp the faster the reaction how does concentration (or pressure of gases) affect rate of reaction - Answer the more the concentration the faster the reaction how does surface area affect the rate of reaction - Answer the larger the ...

Lithium(flame) - Answer Crimson Sodium(flame) - Answer Yellow Potassium(flame) - Answer Lilac Calcium(flame) - Answer orange/red Lithium(flame) - Answer Crimson copper(flame) - Answer green Magnesium(flame) - Answer No colour/white copper - Answer blue precipitate when sodium hydroxide added Iron(II) - Answer green precipitate when sodium hydroxide added Iron(III) - Answer brick red precipitate when sodium hydroxide added calcium - Answer white...

Mixture - Answer made up of two or more substances that are not chemically combined 3 properties of compounds - Answer -fixed composition, the same ratio of each element -only chemical reactions can separate elements -chemical bonds between atoms 3 properties of mixtures - Answer -no fixed composition, the amount of the different substances can change -can be separated easily, using the properties of the different substances -no chemical bonds between atoms/compound in mixtur...

Air - Answer A mixture of gases. 78% Nitrogen, 21% Oxygen, 0.04% carbon dioxide and other gases. Global Warming - Answer The rise in mean surface temperatures on the earth, thought to be due to increasing amounts of greenhouse gases such as carbon dioxide Greenhouse gas - Answer A gas in the atmosphere that contributes to the greenhouse effect , such as carbon dioxide Photosynthesis - Answer The process where green plants made glucose, by taking in carbon dioxide and producing o...

How metals can be placed in order of reactivity - Answer By their reactions with water and dilute acid When metals react with water or dilute acids - Answer Hydrogen gas is given off. The gas 'pops' with a lighted spill. OIL RIG - Answer oxidation is loss (of electrons), reduction is gain (of electrons) A more reactive metal - Answer Will displace a less reactive metal from its aqueous solution The non-metals hydrogen and carbon - Answer can be given positions in the reac...

What is electrolysis? - Answer The breaking down of a substance using electricity Types of electrolysis - Answer Of aqueous ionic compounds Of molten ionic compounds Ionic compound - Answer a compound composed of positive(cations) and negative ions(anions) Why can't ionic compounds conduct electricity as solid? - Answer The electrons aren't free to move and carry the charge through the structure What is an electrolyte? - Answer a liquid/solution that conducts electricit...

What is an exothermic reaction? - Answer A reaction that causes a rise in temperature to surroundings- it releases energy What is an endothermic reaction? - Answer A reaction that causes a decrease in temperature in the surroundings-it takes in energy If a reversible reaction if exothermic in one direction what will it be in the reverse direction? - Answer Endothermic What must happen for bonds to be broken in a chemical reaction? - Answer Reacting particles must collide with su...