[20.2] the pH scale and strong acids

Question 1

describe the relationship between pH and concentration of H+ (aq)

Answer 1

• low value of [H+(aq)] = high value of pH
• high value of [H+(aq)] = low value of pH

Question 2

how do you calculate pH using [H+(aq)]?

Answer 2

pH = -log[H+(aq)]

always give to 2dp

Question 3

how do you calculate [H+(aq)] using pH?

Answer 3

[H+(aq)] = 10⁻ᵖᴴ

always give to 3sf

Question 4

calculating the pH of strong acids

Answer 4

• a strong monobasic acid, HA, completely dissociates in an aqueous solution
• for a strong acid, [H+(aq)] = [HA (aq)]
• pH can be calculated directly from the concentration of the acid

Question 5

what is a strong acid?

Answer 5

an acid which completely dissociates in aqueous solution