Rates QQ Trade

Question 1

The minimum amount of energy needed for the particles to react is called the

Answer 1

Activation energy

Question 2

Name the two things the rate of a reaction depends

Answer 2

proper orientation
min energy- EA

Question 3

What factors affect the rate of reactions?

Answer 3

concentration, surface area, temperature, catalyst, and pressure

Question 4

As the reaction progresses, what happens to the concentration of reactants

Answer 4

it decreases

Question 5

if a reaction involves HCl, give 2 possible ways to monitor the rate

Answer 5

pH and conductivity

Question 6

what is the mathematical expression of rate of reaction

Answer 6

Rate=∆[A]/ ∆t

Question 7

The change in concentration over a given time is called

Answer 7

average rate

Question 8

the change in concentration at a given time is called

Answer 8

instantaneous rate

Question 9

How does an increase in temperature increase the rate of the reaction

Answer 9

increase kinetic energy

Question 10

A substance that increases the rate of a chemical reaction without being used up

Answer 10

catalyst

Question 11

how does a catalyst affect the rate of a reaction

Answer 11

reduce activation energy

Question 12

which graph shows as the temperature increases, a larger population of molecules has higher energy

Answer 12

Maxwell-boltzmann distributions

Question 13

how do you represent the activation energy on a graph

Answer 13

from the starting point to the hump (activated complex)

Question 14

what is the highest point on the potential energy graph called

Answer 14

transition state

Question 15

what is the name of the species that is an intermediate between reactants and products in a chemical reaction

Answer 15

activated complex

Question 16

what is the sequence of events that describes the actual process by which reactants become products

Answer 16

reaction mechanism

Question 17

each single step in a reaction is called

Answer 17

elementary step

Question 18

what is the name of a reaction that has 3 molecules in its elementary step or slow step

Answer 18

termolecular

Question 19

what is the slow step in a reaction called?

Answer 19

rate determining step, RDS

Question 20

the species that is formed in one reaction and then used up in another is called

Answer 20

intermediate

Question 21

the species that is put in one step and regenerated at the end of the reaction is called

Answer 21

catalyst

Question 22

if a solid reactant is crushed, the reaction rate increases, what factor did this

Answer 22

surface area

Question 23

what is the unit for rate

Answer 23

Mol/L time

Question 24

what is the rate expression for the reaction 2A -> 3B?

Answer 24

Rate = -1∆[A]/2∆t = 1∆[B]/3∆t

Question 25

if the concentration of a reactant does not affect the rate, what is the order of the reaction?

Answer 25

zero order

Question 26

what does a first order reaction mean

Answer 26

concentration affects the rate -> directly, proportional

Question 27

what does a second order reaction mean

Answer 27

rate is affected by concentration squared

Question 28

factors that affect reaction rates

Answer 28

-concentration of reactants (as [] increases so does likelihood of collisions) -temperature (high temp=more collision) -surface area (more surface area=more collisions= higher rate) -pressure (for gasses, more pressure=more collisions=higher rate) -catalyst (decreases activation energy of reaction)

Question 29

Rate equation and units

Answer 29

Rate= ∆[]/∆T Mol/Lsec

Question 30

Measuring reaction rates

Answer 30

1. monitoring mass - when gas is released the reduction in mass of the product can be measured (Rate =∆m/∆t) 2. volume - rxns that generate gas, the volume of gas can be monitored (Rate=∆vol/∆t) 3. pH - when an acid or base is present, then changes in pH can be measure (Rate= ∆pH/∆T) 4. conductivity - dissolved ions in aqueous solution conduct electricity 5. pressure -for rxns involving gasses on both sides of equation. Change in moles, pressure censor used to measure ∆ in pressure (Rate=∆p/∆t) 6. Absorbance -for coloured solutions, monitor absorption of light using spectometry -absorption of light is directly related to concentration (Rate=∆absorption/∆t)