Reaction Rates and Equilibrium

Question 1

what is the formula for rate

Answer 1

change in concentration/ time (seconds)

Question 2

what conditions makes a collision effective?

Answer 2

1) particles collide with the correct orientation
2) particles have sufficient energy to overcome activation energy

Question 3

how can you determine rate of reaction??

Answer 3

1) measure the decrease in concentration of a reactant
2) measure the increase in concentration of a product

Question 4

how can you determine rate of reaction of a gas?

Answer 4

1) measure decrease in mass of reactants
2) monitor volume of gas at regular time intervals

Question 5

what is a catalyst?

Answer 5

a substance that increases rate of reaction by providing alternate pathway with lower activation energy without being used up

Question 6

what is a catalyst?

Answer 6

a substance that increases rate of reaction by providing alternate pathway with lower activation energy without being used up

Question 7

what is a homogenous catalyst

Answer 7

a catalyst that has the same physical state as the reactants.

Question 8

how does a homogenous catalyst work?

Answer 8

catalyst reacts with reactants to form an intermediate which then breaks down to give the product and regenerate the catalyst

Question 9

what are 2 examples of homogenous catalust

Answer 9

1) making esters with sulfuric acid as a catalyst
ethanoic acid and ethanol react to form the ester ( CH3COOC2H5) and h20
2) ozone depletion with chlorine radicals as catalyst
2o3 + chlorine radical —– 3o2

Question 10

what are 2 examples of homogenous catalust

Answer 10

1) making esters with sulfuric acid as a catalyst
ethanoic acid and ethanol react to form the ester ( CH3COOC2H5) and h20
2) ozone depletion with chlorine radicals as catalyst
2o3 + chlorine radical —– 3o2

Question 11

what is a heterogenous catalyst

Answer 11

A heterogenous catalyst has a different physical state than its reactants

Question 12

how does a heterogenous catalyst work

Answer 12

reactant molecules are weakly adsorbed onto to surface of catalyst where reaction takes place and the product leaves the catalyst by desorption

Question 13

what is autocatalysis

Answer 13

when the product of a reaction acts as a catalyst then speeds up the reaction as more is formed

Question 14

what does le chateliers principle say

Answer 14

when a system in equilibrium is affected by an external , the system adjusts to the change to minimise affect of the change.

Question 15

what does an increase in temperature shift equilibrium to?

Answer 15

increase in temperature shifts equilibrium to the endothermic side

Question 16

what does a decrease in temperature shift equilibrium to?

Answer 16

decrease in temperature shift equilibrium to the exothermic side

Question 17

how does an increase in pressure affect equilibrium position?

Answer 17

an increase in pressure shifts equilibrium to the side with fewer moles

Question 18

what is the formula for equilibrium constant?

Answer 18

[A]a [B]b

Question 19

what does a Kc value of 1 show?

Answer 19

indicates an equilibrium position halfway between reactants and products

Question 20

what does a Kc value of more than one show?

Answer 20

indicates equilibrium position is towards products

Question 21

what does a Kc value of less than one show?

Answer 21

indicates equilibrium position is towards reactants

Question 22

what colour is chlorine water

Answer 22

colourless

Question 23

what colour is bromine water

Answer 23

orange

Question 24

what colour is iodine water

Answer 24

brown

Question 25

what does chlorine water form when added to KCL

Answer 25

colourless, no reaction

Question 26

what colour does chlorine water form when added to KBr

Answer 26

orange as bromine is displaced by chlorine and bromine is orange

Question 27

what colour does chlorine water form when added to KI

Answer 27

brown as iodine is displaced by chlorine and iodine is brown

Question 28

what colour does chlorine water form when added to KI

Answer 28

brown as iodine is displaced by chlorine and iodine is brown

Question 29

what colour does bromine water form when added to KCL

Answer 29

no change in colour so remains orange as bromine is less reactive

Question 30

what colour does bromine water form when added to KBr

Answer 30

colour remains orange as there is no reaction

Question 31

what colour does bromine water form when added to KI

Answer 31

colour turns brown as iodine is displaced by bromine and iodine is brown

Question 32

what colour does iodine water from when added to KCL and KBr and KI

Answer 32

colour remains brown as doesnt displace any of the halogens

Question 33

what is the order of reactivity of chlorine, bromine and iodine

Answer 33

chlorine> bromine>iodine