Acids, Bases And PH

Question 1

Acid + base?

Answer 1

Salt and water = neutralisation

Question 2

Strong acids?

Answer 2

Hydrochloric, sulphuric, nitric

usually complete dissociation

Question 3

HCl and benzene?

Answer 3

HCl dissolves in benzene, an organic solvent. It is not acidic because benzene is non polar and doesn’t ionise H+

Question 4

What is the equilibrium constant?

Answer 4

Ka = [OH-] [H+] / [A-]

Question 5

What is an alkali?

Answer 5

A base that dissolves in water

Question 6

What are some insoluble bases?

Answer 6

CuO and MgO

Question 7

What is an alkali example?

Answer 7

KOH

Question 8

What are some strong bases?

Answer 8

K, Na, Ca, Ba and Li

Question 9

What are amphoteric bases?

Answer 9

They show characteristics of acids and bases [Al(OH3)]

Question 10

What is the PH scale?

Answer 10

pH = -log[H+]
[H+] = 10^pH
measures the acidity of a solution

Question 11

What is the ionisation of water?

Answer 11

H2O + H2O = H3O+ + OH-

only a small proportion does this

Question 12

What is the ionic product of water?

Answer 12

Kw - at 25 degrees kw =

[H+][OH-] = 1.0 x 10^-14 mol^2 L^-2

Question 13

What is the PH of seawater?

Answer 13

8.2

Question 14

What do buffers do?

Answer 14

They resist changes in pH
weak acid + its salt
weak base + its salt