Question

When chlorine reacts with water, the resulting solution is weakly acid and reacts with sliver nitrate to give a white precipitate. Write balanced equations to represent these reactions. Explain why manufactures of household bleaches add bases such as sodium hydroxide to their products to increase their effectiveness.

Answer 1

Cl2(g) + H2O(l) -------------------> HOCl(aq) + HCl(aq)

Cl2(g) + H2O(l) +AgNO3(aq)----------> AgCl(s)+HOCl(aq)+HNO3(aq)

Sodium hypochlorite is bleaching agent, usually as a dilute (3–6%) solution in water. This solution of sodium hypochlorite, commonly referred to as simply "bleach", was also one of the first mass-produced bleaches. It is produced by passing chlorine gas through a dilute sodium hydroxide solution

Cl₂ (g) + 2 NaOH (aq) → NaCl (aq) + NaClO (aq) + H₂O (l)

due to transport and handling safety concerns, the use of sodium hypochlorite is preferred over chlorine gas in water treatment.