Acids, Bases & Salts (C10)

You are provided with 90 mL of distilled water and 10 mL of concentrated sulphuric acid to prepare dilute sulphuric acid.

  1. What is the correct way of preparing dilute sulphuric acid? Give reason.
  2. How will the concentration of H3O+ ions change on dilution?

Answer

(i) Add 10 mL of concentrated sulphuric acid slowly to 90 mL of water with constant stirring.

Dilution of acid is a highly exothermic process. If water is added to concentrated sulphuric acid, heat generated causes the mixture to splash leading to burns and the glass container can break.

(ii) Decreases per unit volume.