6A: Buffer And Titrations

Question 1

What does the term: buffer effectiveness mean and what are the two factors

Answer 1

There is a limit to how much acid or base can be added to the buffer before its pH changes significantly
1. The relative amounts of acid and base
2. The absolute concentrations of acid and base

Question 2

Buffering range

Answer 2

The pH range at which the buffer can be most effective

Question 3

The buffering capacity

Answer 3

The amount of acid or base a buffer can comfortably neutralize

Question 4

What ratio is a buffer most effective

Answer 4

0.1<[base]:[acid]<10
PH=pkA-1
PH=pKa+1

Question 5

1. What is the buffering Capacity equation
2. Buffer capacity and concentration of buffer relationship
3. What is the best capacity

Answer 5

1. B=dnbase/dpH
2. Capacity increases with increasing absolute concentration of buffer components
3. Base:acid=1

Question 6

What is the buffering capacity involving acids and bases
When does the expression reach a maximum

Answer 6

B=ln(10)x(nA—nHA)/(nA-+nHA)
NA-=nHA

Question 7

What is occurring in a titration

Answer 7

A solution of a known concentration is gradually added to another solution of unknown concentration until the chemical reaction between the two solutions is complete

Question 8

Equivalence point

Answer 8

The point at which the reaction is complete

Question 9

Indicator

Answer 9

Substance changing color at the equivalence point

Question 10

How many equivalence points will there be for a TRIprotic acid

Answer 10

3 different equivalence points

Question 11

Why is it important to select the right indicator

Answer 11

The indicator must change its color at or near the equivalence point for the titration curve