Q. Horrock’s apparatus estimates:
a. Free cholorine
b. Combined Chlorine
c. a+b
d. Chlorine demand.
Correct answer : d
Horrocks Apparatus :
• It is used to find out the dose of bleaching powder required for disinfection of water.
• It consists of :
• One black cup (200 ml ) with a marking inside.
• Six white cups (200 ml ).
• Seven glass stirring rods.
• One pipette.
• Two droppers.
• Starch-iodide indicator solution.
• Bleaching powder.
• Two metal spoons which can hold 2 gms of bleaching powder in each.
• Plastic or wooden box container for all these items.
