A2 acids and bases.

Question 1

Acid + base.

Answer 1

Salt and water.

Question 2

Acid + carbonate.

Answer 2

Salt, water and CO2.

Question 3

Acid + metal.

Answer 3

Salt and hydrogen.

Question 4

Base definition.

Answer 4

Neutralises an acid to form a salt.

Question 5

Alkali definition.

Answer 5

A base that dissolves in water releasing OH- ions.

Question 6

Salt definition.

Answer 6

A substance produced by the reaction of an acid with a base.

Question 7

Bronsted-lowry acid and bases definition.

Answer 7

Acid- proton donor
Base- proton acceptor.

Question 8

Conjugate acid base pairs definition.

Answer 8

2 species that can be intro converted by the transfer of a proton.

Question 9

Monobasic, dibasic and tribasic acids.

Answer 9

Refer to the total number of hydrogen ions that can be replaced per molecule in an acid-base reaction.

Question 10

What type of scale is the pH scale?

Answer 10

Logarithmic as each increase/decrease in number means a 10x difference.

Question 11

Conversion between H+ and pH values.

Answer 11

pH= -log(H+)
10^-pH= H+.

Question 12

Calculating the pH of strong acids.

Answer 12

Can be calculated directly from the H+ concentration.

Question 13

Kw definition.

Answer 13

The ionic product of water
(H+) x (OH-)
1.00 x 10^-14 mol2dm-6.

Question 14

How to calculate weak and strong base pH.

Answer 14

Weak= similar to weak acid
Strong= using Kw and OH- concentration.

Question 15

Weak acid dissociation equation.

Answer 15

HA–> H+ + A-.

Question 16

Ka expression.

Answer 16

(H+)(A-)/(HA)
Used for weak acids
Acid dissociation constant.

Question 17

What does a large value of Ka indicate.

Answer 17

The equilibrium is more towards the right= greater dissociation= greater acid strength.

Question 18

Converting between pKa and Ka.

Answer 18

pKa= -logKa
10^-pKa=Ka.

Question 19

Relationship between acid strength, pKa and Ka.

Answer 19

Stronger acid= large Ka= smaller pKa
Weaker acid= small Ka= larger pKa.

Question 20

Approximations assumed when calculating the pH of a wrak acid using Ka.

Answer 20

1) That the H+ conc from the dissociation of water is so small that it can be neglected
2) As the dissociation of weak acids is small, it is assumed that there is no decrease/can be neglected in the HA concentration from dissociation.

Question 21

Ka simplified expression used for weak acids w/ the assumptions.

Answer 21

(H+)^2 eqm /HA start.