Residual chlorine & Chlorine Demand - Viva

At what pH, chlorine exists as molecular chlorine?

• 3

• 5

• <5

• <10

Which of the following is termed as free available chlorine?

• Hypochlorous acid

• Hypochlorite ions

• Molecular chlorine

• All of the above

When the pH is between 5 and 10, the chlorine in the water acts as ______

• Hypochlorous acid

• Hypochlorite ions

• Molecular chlorine

• Hypochlorous acid hypochlorite ions

At what pH, chlorine in water acts as only hypochlorite ions?

• <5

• >5

• <10

• >10

Chlorine which gets consumed in the oxidation of impurities before disinfection is ______________

• Free chlorine

• Residual chlorine

• Chlorine demand

• Residual demand

The chlorine, which serves as a disinfectant is ___________

• Free chlorine

• Free Residual chlorine

• Chlorine demand

• Residual demand

The permissible limit of free residual chlorine is ___________ppm

• 0.2

• 0.6

• 1

• 10

What is the chemical formula of bleaching powder?

• Ca (OCl)2

• Ca (OCl)

• Ca (OCl)3

• CaCl2

The hypochlorous acid is ______ times effective as hypochlorite ions.

• 50

• 10

• 80

• 5

The process of chlorination with hypochlorites is called ___________

• Super chlorination

• Pre chlorination

• Post chlorination

• Hypo-chlorination