Question

Which of the following mixtures will result in a buffer solution?

I: 300 mL of 0.20 M HClO2 added to 100 mL of 0.40 M NaClO2

II: 100 mL of 0.40 M NaOH added to 200 mL of 0.20 M HClO2

III: 200 mL of 0.10 M HCl added to 300 mL of 0.20 M NaClO2

Answer 1

I) HClO2 is weak acid

NaClO2 is salt of HClO2

so mixture of HClO2 and NaClO2 act as acidic buffer.

II) total HClO2 convert to NaClO2.

so cannot act as buffer.

III) some NaClO2 convert to HClO2.

so solution contain HClO2 and NaClO2

so can act as buffer

answer = I and III