c5 - rates of reaction

Question 1

equilibrium

Answer 1

a state in a reaction where the rate of the forward reaction is equal to the rate of the reverse reaction

Question 2

le chatelier’s principle

Answer 2

if a system is at equilibrium and a change is made to any of the conditions then the system responds to counteract that change

Question 3

dynamic equilibrium

Answer 3

where forward and backward reactions are happening at the same rate

Question 4

effect of increasing temperature on equilibrium

Answer 4

shifts equilibrium to favour endothermic reaction

Question 5

effect of decreasing temperature on equilibrium

Answer 5

shifts equilibrium to favour the exothermic reaction

Question 6

effect of increase of concentration of reactants in a reaction (3)

Answer 6

equilibrium shifts to right to make more product bringing it back to equilibrium

Question 7

effect of increasing concentration of products in a reaction (3)

Answer 7

equilibrium shifts to left to make more product bringing it back to equilibrium

Question 8

effect of increasing pressure of gas in reaction

Answer 8

equilibrium shifts to favour the reaction with less particles as this will decrease the pressure

Question 9

effect of decreasing pressure of gas in a reaction

Answer 9

equilibrium shifts to favour the reaction with most particles as this will decrease the pressure

Question 10

activation energy

Answer 10

minimum energy required for a chemical reaction to take place

Question 11

collision theory

Answer 11

the theory states that for a chemical reaction to happen particles must collide with sufficient energy

Question 12

frequency

Answer 12

the amount of times something happens in a second

Question 13

concentration

Answer 13

number of particles in a given volume

Question 14

factors effecting rate of reaction

Answer 14

• temperature
• pressure
• concentration of solution
• surface area
• presence of a catalyst

Question 15

in reference to collision theory

what two things does rate of reaction depend on

Answer 15

• frequency of collisions between particles
• the energy with which the particles collide

Question 16

what is the relationship between concentration and rate of reaction

Answer 16

directly proportional , if u double concentration u double the rate

Question 17

collision theory in reference to temperature (3)

Answer 17

when u increse temperature the particles will move faster causing more frequent succesful collisions between particles. speed also causes particles to collide with more energy meaning activation energy is likely exceeded

Question 18

collision theory in reference to concentration

Answer 18

if concentration is incresed there are more particles in a given volume causing more frequent succesful collisions causing rate of reaction to increase as it is directly proportional to concentration

Question 19

collision theory

collision theory in reference to surface area

Answer 19

when you increase the surface area of a solid u increase the number of particles available for collision causing there to be more frequent succesful collisions increasing the rate of reaction

Question 20

collision theory in reference to pressure

Answer 20

when pressure is increased in a gaseous reaction the rate will increase as there are more particles in a given volume of gas causing more frequent successful collisions

Question 21

mean rate of reaction formula

Answer 21

quantity of reactant used / time taken
or
quantity of product formed / time taken

Question 22

units for rate of reaction

Answer 22

The units of rate of reaction may be given as g/s, cm3/s or mol/s.

Question 23

how do you calculate specific rate of reaction

Answer 23

Draw a tangent at the specific time and calculate the gradient.

Question 24

define reversible reactions in terms of energy changes

Answer 24

If a reversible reaction is exothermic in one direction, it is endothermic in the opposite direction. The same amount of energy is transferred in each case.