What is the volume (in mL ) of 20 vol H ₂ O ₂ required to completely react with 500 ~mL of 0.02 M acidified KMnO ₄ solution?

Step-by-step solution

Given, Volume of acidified KMnO ₄ solution =500 ~mL Molarity of acidified KMnO ₄ solution =0.02 M Volume strength of H ₂ O ₂=20 vol Normality = Volume strength Equivalent weight Normality for H ₂ O ₂= 20 5.6 =3.57 ~N For KMnO ₄ , reaction is in acidic medium, thus valence factor is 5 . Mn ⁷⁺+5 e⁻ Mn ²⁺ Thus, normality for KMnO ₄= Molarity 5 Now, applying normality equation, aligned N₁ V₁ ( H ₂ O ₂ ) & =N₂ V₂ ( KMnO ₄ ) 3.57 V₁ & =0.02 5 500 V₁ & = 50 3.57 =14.0 ~mL aligned Hence, option (a) is the correct answer.