F325 - Rates, Equilibrium and pH

Question 0

Describe zero order.

Answer 0

The rate is unaffected by changing the concentration in A.

Question 1

What is the rate of reaction?

Answer 1

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

Change in conc/time

Question 2

Describe first order.

Answer 2

Proportional to the increase in concentration.

Eg increase of 3 then increase of 3.

Question 3

Describe second order.

Answer 3

Increases proportional to the square of the concentration.
Eg concentration increases by 3.
Rate increases by 9.

Question 4

What does a half life graph look like for first order?

Answer 4

Constant half life.

Question 5

Describe a zero order Half life graph.

Answer 5

Half life decreased with time at a constant rate.

Question 6

Describe a second order half life graph.

Answer 6

1/x

Question 7

What changes Kc?

Answer 7

Temperature

Question 8

What does a Kc value of 1 indicate?

Answer 8

Equilibrium is halfway between reactants and product

Question 9

What does a Kc above 1 suggest.

Answer 9

Product favoured, shifts to the right.

Question 10

When the forward reaction is endothermic how does Kc increase?

Answer 10

As temperature increases so does Kc.

Question 11

What is Kc?

Answer 11

Products/reactions

Question 12

Why is a Brønsted-Lowry acid and base?

Answer 12

Acid: any substance for which a proton can be removed.

Base: any substance that can remove a proton from an acid.

Question 13

What is an alkali?

Answer 13

A base that dissolved in water forming OH- ions.

Question 14

What is an acid base conjugate pair?

Answer 14

A pair of two species that transform into each other by gain or loss of a proton.

Question 15

What is pH?

Answer 15

-log[H+]

Question 16

What I [H+]?

Answer 16

10^-pH

Question 17

What is a strong and weak acid?

Answer 17

Strong completely dissociates in water.

Weak partially dissociates in water.

Question 18

In a strong acid what does H+ equal?

Answer 18

[H+]=[HA]

Question 19

What does [H+] equal in weak acids?

Answer 19

[H+]=[A-]

Question 20

Describe Kw in water, acidic and alkaline solutions.

Answer 20

Water H+=OH-

Acid H+>OH-

Alkaline H+<OH-

Question 21

What is Kw?

Answer 21

[H+][OH-] both (aq)

1 x 10^-14

Question 22

What is a buffer solution?

Answer 22

A mixture that minimises pH changes on addition of small amounts of acid or base.

Question 23

How is a buffer solution made?

Answer 23

A mixture of a weak acid and it’s conjugate base.

Question 24

Describe the action of a buffer solution HA.

Answer 24

HA ~ H+ + A-

When H+ is added A- reacts and eq shift to the left removing the H+ ions.

When OH- is added H+ react and eq shifts to the right.

Question 25

What is equivalence point?

Answer 25

The point in a titration at which the volume of one solution has reached exactly the volume of the second solution.