rate of reaction (A1)

Question 1

affect of concentration on rate of reaction

Answer 1

higher concentration increases rate as there are more particles which collide with eachother more frequently as they are closer together

Question 2

affect of gas pressure on rate of reaction

Answer 2

higher pressure increases rate as gas molecules are closer together so collide more frequently

Question 3

the role of a catalyst

Answer 3

a catalyst is a substance that increases the rate of a chemical reaction by providing an alternate reaction pathway with a lower activation energy. the catalyst is not used up in the chemical reaction.

Question 4

homogeneous catalyst

Answer 4

same physical state as the reactants

Question 5

heterogeneous catalyst

Answer 5

different physical state as the reactants

Question 6

why are catalysts economically and sustainably important?

Answer 6

lower temperatures needed as activation energy is lower. this reduces energy demand from fossil fuel consumption which therefore reduces CO2 emissions

Question 7

explain why an increase in temperature increases the rate of a reaction in terms of the Boltzmann distribution

Answer 7

a higher proportion of molecules have greater than/equal energy to the activation energy required and so there are more successful collisions

Question 8

explain why the use of a catalyst increases the rate of a reaction in terms of the Boltzmann distribution

Answer 8

a higher proportion of molecules now exceed the new (lower) activation energy and so there are more successful collisions