Factors affecting Reaction rate

Question 1

Rate of reaction is

Answer 1

how quickly the rate of reactant or product changes with respect to time

Formula delta[p]/delta t

(-)delta[R]/’delta t

units moldm^-3s^-1

Question 2

what is R

Answer 2

R is obtained in terms of concentrations of the chemicals involved in the RDS during the reaction

Question 3

the reactivity of reactants depends on their tendency to ?

and why does this affect reaction rates

Answer 3

form bonds, some are naturally fast and some are naturally slow

ex rusting, as it is slow as electrons are not lost easily in the reaction

it affects reaction rates because some reactants react faster and slower so it gives an explanation

Question 4

2. Ability of reactants to meet
   how does this affect Rate of reaction

Answer 4

this affects rate of reaction as reactants must come in contact to react, which is why reactants such as gasses/liquids have faster reactions because they come into contact faster.

Furthermore, an increase in surface area also increases reaction rate

Question 5

3. concentration of reactants

and you need to memorize the example

Answer 5

this affects reaction rates as higher concentration = more collisions

wood burns fastest in pure oxygen but not in normal air

Question 6

4. Temp of system

Answer 6

higher temp = more collision
higher temp = higher speeds that results in more particles reaching activation energy

Question 7

Catalyst

Answer 7

lower Ae so more reactions occur which makes reaction faster

Question 8

what is the rate law

Answer 8

the purpose of the rate law is to tell us the relationship between the change in concentration of the reactants and the rate of the equation

Question 9

how are rate law and reaction mechanism related

Answer 9

The slowest step in a reaction mechanism is known as the rate-determining step. The rate-determining step limits the overall rate and therefore determines the rate law for the overall reaction.

Question 10

what is the reaction mechanism

Answer 10

it is a series of elementary steps by which the chemical reaction occurs

Question 11

why is using the balanced equation of a chemical reaction a bad idea to find rate

Answer 11

it only shows the stoichiometry of the reaction. Reaction rate depends on factors such as concentration and temperature.

Question 12

activated complex definition

Answer 12

complex formed when the reactants just reached the amount of energy required and are starting to form products

Question 13

activation energy definition

Answer 13

the minimum amount of kinetic energy that reactants must posses in order to form products

Question 14

why do industries want to know about rates of reactions

Answer 14

By finding out how fast products are made and what causes reactions to slow down we can develop methods to improve production of products. for example finding the best catalyst to improve reaction rate.

Question 15

what are assumptions made in calorimetry

Answer 15

1. no heat is transferred between the calorimeter and the outside environment.
2. any heat absorbed or released by the calorimeter materials is negligible.
3. a solution has the same heat
   capacity as water

Question 16

when the Ea is small, the reaction tends to beeee

Answer 16

exothermic

Question 17

When the Ea is large, the reaction tends to be

Answer 17

endothermic

Question 18

Why are reaction mechanisms imp

Answer 18

they are important because the allow us to break down the steps into a series of two body collisions as three bodies colliding at once is unlikely

Question 19

purpose of rate law?

Answer 19

expresses the way that the change in concentration of reactants ([reactants]) affects the rate of a reaction.

Question 20

are the exponents in the rate law only able to be found in experiments?

Answer 20

yes

Question 21

what is the difference between rate law and Arrhenius equation

Answer 21

the rate law tells us how the speed of the reaction varies with concentration although the Arrhenius equation tells us the effect of a change of temperature on the rate constant, and consequently on the rate of the reaction.