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Flashcards in Module 5.1 Deck (40)
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1

Define rate of reaction

The change in concentration of a reactant or product per unit of time

2

List ways in which we can measure the rate of reaction?

Measure the loss in mass
Measure how fast a gas in produced
Measure how long it takes for a solution to go cloudy
Measure the pH change of a reaction
Watch for colour change

3

When measuring a change in mass, what should you use?

A weighting scale

4

When measuring how fast a gas is produced, what should you use?

A gas syringe

5

When measuring how long it takes for colour change, what should you use?

Colourimetry

6

What is meant by order?

With respect to a reactant, the order is the power to which the concentration of a reactant is raised to in the rate equation

7

What 3 orders must we be aware of?

Zero order
First order
Second order

8

What does the concentration-time graph of a zero order reactant look like?

Straight line downards

9

What does the rate-concentration graph of a zero order reactant look like?

Straight line

10

With zero order reactants, what will happen to the rate, if the concentration of the reactant is changed?

Nothing

11

With zero order reactants, what pattern does its half-life follow?

DECREASES with time

12

What does the concentration-time graph of a first order reactant look like?

Slopes downwards

13

What does the rate-concentration graph of a first order reactant look like?

Straight line upwards

14

With first order reactants, what will happen to the rate, if the concentration of the reactant is changed?

The rate changes by a proportionally equal amount

15

With first order reactants, what pattern does its half-life follow?

Constant

16

What does the concentration-time graph of a second order reactant look like?

Slopes downwards

17

What does the rate-concentration graph of a second order reactant look like?

Slopes upwards (exponential growth)

18

With second order reactants, what will happen to the rate, if the concentration of the reactant is changes by X?

The rate will change by X^2

19

With second order reactants, what pattern does its half-life follow?

Increases with time

20

Define overall order

The sum of the orders of all the different reactants

21

If the overall order of a reaction is 0, what units does the rate constant have?

mol dm^-3 s^-1

22

If the overall order of a reaction is 1, what units does the rate constant have?

s^-1

23

If the overall order of a reaction is 3, what units does the rate constant have?

dm^3 mol ^-1 s^-1

24

If the overall order of a reaction is 4, what units does the rate constant have?

dm^6 mol ^ -2 s^-1

25

What is meant by the rate constant?

The constant that links the rate of reaction with the concentration of the reactants raised to the powers of their orders in a rate equation

26

What form do rate equations take?

r = k[A]^m x [B]^n

Where A is the concentration of reactant A
Where B is the concentration of reactant B
Where m is the order of reactant A
Where n is the order of reactant B

27

Define the term half-life

The time taken for HALF of the reactant to be used up

28

What is the half-life pattern for zero order reactants?

Decreases with time

29

What is the half-life pattern for first order reactants?

Remains constant throughout the reaction

30

What is the half-life pattern for second order reactants?

Increases with time