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DATA TABLE Buffer A Buffer B Mass of NaC 2 H 3 O 2 used to prepare buffer (g) 0.

ID: 534934 • Letter: D

Question

DATA TABLE

Buffer A

Buffer B

Mass of NaC2H3O2 used to prepare buffer (g)

0.149 g

1.49 g

Volume of buffer prepared (mL)

100.0

100.0

Molar concentration of HC2H3O2 in buffer (M)

0.1

1.0

Initial pH of buffer

4.24

4.33

Volume of 0.5 M NaOH to raise pH by 2 units (mL)

1.5

19.0

Volume of 0.5 M HCl to lower pH by 2 units (mL)

1.0

5.0

Volume of 0.5 M NaOH at equivalence point (mL)

1.75

19.75

DATA ANALYSIS

1.   Write reaction equations to explain how your acetic acid-acetate buffer reacts with an acid and reacts with a base.

Buffer A

Buffer B

Mass of NaC2H3O2 used to prepare buffer (g)

0.149 g

1.49 g

Volume of buffer prepared (mL)

100.0

100.0

Molar concentration of HC2H3O2 in buffer (M)

0.1

1.0

Initial pH of buffer

4.24

4.33

Volume of 0.5 M NaOH to raise pH by 2 units (mL)

1.5

19.0

Volume of 0.5 M HCl to lower pH by 2 units (mL)

1.0

5.0

Volume of 0.5 M NaOH at equivalence point (mL)

1.75

19.75

Explanation / Answer

Let, base = NaOH and acid = HCl

So acetic acid-acetate buffer will react in the manner as:

CH3COOH + NaOH = CH3COONa + H2O
CH3COO- + HCl = CH3COOH + Cl-

ie weak acid and its sodium salt will be form as products.