Reaction Kinetics

Question 1

definition of order of reactions

Answer 1

shows how the concentration of each reagent affects rate of reaction

Question 2

definition of order of reaction with respect to a reactant

Answer 2

power to which the concentration of reactant is raised in the rate equation

Question 3

describe reaction rate/concentration of reactant graph

Answer 3

straight across = 0
linear = 1
increasing = 2

Question 4

describe concentration of reactant/time graph

Answer 4

linear down = 0
curve = 1
more decrease = 2

Question 5

describe zero order

Answer 5

half life decreases

conc. doesn’t affect rate of reaction

Question 6

describe first order

Answer 6

concentration of one reactants affects rate of reaction

half life is constant

Question 7

describe second order

Answer 7

concentration of two reactants affects rate

half life increases

Question 8

what is a rate constant

Answer 8

represents how fast a reaction is going in reaction

Question 9

units for rate constant

Answer 9

mol
dm-3
s-1

Question 10

how do you calculate rate

Answer 10

rate = k[X][Y]

Question 11

how to calculate half life

Answer 11

0.693/k

Question 12

what does rate equation show

Answer 12

reactants in rate determining step/slow step/making the intermediate for slow step

Question 13

reaction mechanism

Answer 13

A → B (fast)
B + C → D (slow)
A → B (slow)
B + C → D (fast)

Question 14

what is the rate eqn for
A → B (slow)
B + C → D (fast)

Answer 14

Rate = k[A]

Question 15

what is the rate eqn for
A → B (fast)
B + C → D (slow)

Answer 15

Rate = k [A][C]

Question 16

how can data be found to make rate constant

Answer 16

initial rates (measure each reactant) - slow
using data from course of reaction
- sampling
- continuous

Question 17

what is the difference between sampling and continuous

Answer 17

sampling needs quenching to stop/slow reaction

continuous using physical property to be followed

Question 18

definition of catalysis

Answer 18

increase the rate by providing alternative pathway for the reaction with lower activation energy

Question 19

definition of heterogeneous catalysis

Answer 19

occurs when catalyst is at different phase to the reaction mixture.

Question 20

definition of adsorption

Answer 20

the bonding to the surface by the strengthening of those bonds, the covalent bonds between reactants weaken.

Question 21

describe an example of heterogeneous catalysis

Answer 21

iron in haber process
diffusion of nitrogen/hydrogen gas
adsorption: N2 and H2 to surface
reaction: adsorbed nitrogen and hydrogen atoms react on surface = NH3
desorption: bonds between ammonia and surface weaken and break
diffusion of ammonia away

Question 22

how do transition elements work in catalytic converters

Answer 22

adsorption of nitrogen oxides and carbon monoxides

to nitrogen molecules and carbon dioxide molecules

Question 23

definition of homogeneous catalysis

Answer 23

occurs when catalyst is at the same phase as reaction mixture

Question 24

example of homogeneous catalysis

Answer 24

iodine-peroxodisulfate reaction

Fe3+ catalyst

Question 25

how does Fe3+ work in iodine-peroxodisulfate reaction

Answer 25

reaction more likely to occur with opposite charges

check notes for equations