Reactions

Question 1

what is collision theory?

Answer 1

for a particle to react, they have to collide with each other with sufficient energy 

Question 2

what is activation energy?

Answer 2

The minimum energy required for bonds to break

Question 3

How does temperature impact rate of reaction?

Answer 3

increase in temperature Makes the particles gain more thermal energy

make them move faster
colliding more frequently and colliding with more energy

Higher rate of successful collisions

Question 4

How does concentration and pressure affect rate of reaction?

Answer 4

The more particles per unit of volume makes the collisions more frequent

increasing the rate of reaction

Question 5

how does surface area affect rate of reaction?

Answer 5

The larger, the surface area, the increase rate of reaction

Increase in more frequent collisions

Question 6

what has a larger surface area powder, solid, blocks or chunks?

Answer 6

Powder has the highest surface area to volume ratio, which increases frequency of collisions

Question 7

What do catalysts do to reactions?

Answer 7

lowers activation energy by providing an alternative reaction pathway, giving a higher proportion of successful collisions 

Question 8

What happens in the exothermic reaction and some examples?

Answer 8

Energy is released to surroundings via heat
Combustion and neutralisation are examples of exothermic reactions

Question 9

what happens in endothermic reactions and examples of them?

Answer 9

Takes in heat from the surroundings
Photosynthesis, ice melting and alkane cracking examples of endothermic reactions

Question 10

what start of higher in a reaction profile for exothermic reactions

Answer 10

It goes from reactants to products

Question 11

What starts of lower in an endothermic reaction profile?

Answer 11

reactants start of lower in a reaction profile, as energy is absorbed, forming products


Question 12

Is Bond breaking endothermic or exothermic?

Answer 12

Bond breaking is endothermic as it requires energy from the surroundings to break bonds

Question 13

is bond, forming, exothermic or endothermic

Answer 13

it is exothermic as it releases energy to surroundings to form bonds

Question 14

is bond, forming, exothermic or endothermic

Answer 14

it is exothermic as it releases energy to surroundings to form bonds

Question 15

what is bond energy

Answer 15

Amount of energy required to break one mole of a bond

Question 16

How do you calculate overall energy change?

Answer 16

Energy required to break bond - energy released by forming bonds 

Question 17

if overall energy change is negative negative what type of reaction is it?

Answer 17

It is an exothermic reaction as there is a loss of energy

Question 18

How do you investigate rate of reaction?

Answer 18

Disappearing, cross reaction, experiment

Question 19

how do you do a disappearing cross experiment?

Answer 19

Draw cross on white tile place floss over it add sodium thiosulphate to it and then add in a small volume of hydrochloric acid and time how long it takes for the cross to disappear

Question 20

Faster cross disappears =

Answer 20

= Higher rate of reaction

Question 21

how do you calculate rate of reaction

Answer 21

rate =1/time