Volume of formic acid (mL)

Volume of ${\text{S}}_2{\text{O}}_3^{2-}$ (0.01 M) solution (mL)

Recovery (%)

0.1

11.5

125.0

0.3

10.9

118.4

0.5

10.6

115.2

1.0

9.2

100

2.0

9.2

100

3.0

9.2

100