Chapter 18

Question 1

What is the equation for rate of reaction?

Answer 1

change in conc / change in time

Question 2

What are the units for rate of reaction?

Answer 2

moldm-3s-1

Question 3

what do square brackets mean?

Answer 3

concentration of …

Question 4

what is zero order?

Answer 4

when the conc has no effect on the rate

Question 5

what is zero order?

Answer 5

when the conc has no effect on the rate

Question 6

what is first order?

Answer 6

when the rate depends on its concentration raised to the power of one

Question 7

what is first order?

Answer 7

when the rate depends on its concentration raised to the power of one

Question 8

what is second order?

Answer 8

when the rate depends on its conc raised to the power of 2

Question 9

what is the rate equation?

Answer 9

rate = k [A]^m [B]^n

Question 10

what is taking continuous measurements during the course of a reaction called?

Answer 10

Continuous monitoring

Question 11

What can be used to do continuous monitoring when the product is not a gas?

Answer 11

A colorimeter

Question 12

what does zero order on a graph look like?

Answer 12

produces a straight line with a negative gradient, the value of the gradient is equal to the rate constant

Question 13

what does first order look like on a graph?

Answer 13

Produces a downward curve with a decreasing gradient overtime, the half-life is constant

Question 14

What does second order look like on a graph?

Answer 14

produces a downward curve, steep at the start but tailing off more slowly

Question 15

What is half-life and its symbol?

Answer 15

t 1/2 : the time taken for half of the reactant to be used up

Question 16

what is the pattern between first order reactions and half-life?

Answer 16

exponential decay

Question 17

what measurements are plotted on a rate concentration graph?

Answer 17

The rate of reaction a different concentration

Question 18

What shape does zero order produce on a rate concentration graph?

Answer 18

A horizontal straight line with zero gradient

Question 19

what shape does first order produce on a rate concentration graph?

Answer 19

A straight line graph through the origin

Question 20

what shape does second order produce on a rate concentration graph?

Answer 20

An upward curve with increasing gradient

Question 21

how do you find the rate constant on a zero order rate concentration graph?

Answer 21

The intercept on the Y axis

Question 22

how do you determine the rate constant from a first order rate concentration graph?

Answer 22

By measuring the gradient of the straight line

Question 23

What is the rate determining step?

Answer 23

The slowest step in a sequence of reactions

Question 24

what happens to the rate constant as temperature increases?

Answer 24

It also increases

Question 25

what does the Arrhenius equation show us?

Answer 25

An exponential relationship between the rate constant and temperature

Question 26

What is the Arrhenius equation?

Answer 26

k = Ae ^ Ea/RT

Question 27

in the equation, what does the exponential factor represent?

Answer 27

The proportion of molecules that exceed the activation and energy

Question 28

In the equation, what does the pre-exponential term take into account?

Answer 28

The frequency of collisions with correct orientation

Question 29

what graph will we get if ln K is plotted against 1/T?

Answer 29

A downward straight line graph of the type Y = MX + C