C21 - Acids, bases and buffers

Question 1

What is a Bronsted-lowry acid?

Answer 1

It is a proton donor

Question 2

What is a Bronsted-lowry base?

Answer 2

It is a proton acceptor

Question 3

What is a monoprotic acid?

Answer 3

Releases 1 mole of H+ ions per mole of substances e.g. HCl or HNO3

Question 4

What is a diprotic acid?

Answer 4

Releases 2 moles of H+ ions per mole of substances e.g. H2SO4

Question 5

What is a triprotic acid?

Answer 5

Releases 3 moles of H+ ions per mole of substances e.g. H3PO4

Question 6

What is the equation to work out the pH?

Answer 6

pH = -log10(H+)

Question 7

What is the equation to work out the number of H+ ions?

Answer 7

(H+) = 10^-pH

Question 8

How many decimal places is pH left to?

Answer 8

2 dp

Question 9

Do weak acids fully dissociate H+ ions?

Answer 9

No

Question 10

What is the equivalence point?

Answer 10

At the equivalence point in an acid-base titration, moles of base = moles of acid and the solution only contains salt and water

Question 11

What is significant about the half equivalence point?

Answer 11

At this point (A-) and (HA) are equal so therefore Ka = (H+)

Question 12

What is the role of buffer solutions?

Answer 12

Oppose changes in pH when small quantities of acid or base are added

Question 13

What is in an acidic buffer?

Answer 13

Acidic buffer has a weak acid and a salt

Question 14

What is in a basic buffer?

Answer 14

Acidic buffer has a weak acid and a salt