Chlorine

Question 1

Major active molecule for chlorine induced disinfection

Answer 1

HOCl ( HYPOCHLOROUS ACID )

Question 2

Minor active molecule in chlorine induced disinfection

Answer 2

OCl ( HYPOCHLORITE ION )

Question 3

Recommended contact period for residual free chlorine in water ?

Answer 3

1 hour

Question 4

Best pH for chlorine action

Answer 4

7

Question 5

Fresh bleaching powder has_______% chlorine

Answer 5

33%

Question 6

1 chlorine tablet can be used to disinfect _____litres of water

Answer 6

20 litres

Question 7

For rural area best method of purification

Answer 7

Chlorination

Question 8

Interval at which well had to be chlorinated during a coolers epidemic?

Answer 8

Daily

Question 9

Level of free chlorine/ holding level ( in ppm or mg/lit)

In DRINKING WATER

Answer 9

> 0.5 ppm or mg/lit

Question 10

Level of free chlorine/ holding level ( in ppm or mg/lit) in POST-DISASTER

Answer 10

> 0.7 ppm or mg/lit

Question 11

Level of free chlorine/ holding level ( in ppm or mg/lit) in SWIMMING POOL

Answer 11

> 1 ppm or mg/ litre

Question 12

Level of free chlorine/ holding level ( in ppm or mg/lit) in
RISK OF CHOLERA OR OUTBREAK ?

Answer 12

> 2 ppm or mg/lit

Question 13

Level of free chlorine/ holding level ( in ppm or mg/lit) to kill CYCLOPS

Answer 13

> 5 ppm or mg/lit

Question 14

Chlorine kills which organism?

Answer 14

ONLY BACTERIA

Question 15

Chlorine had no effect on?

Answer 15

Bacterial spores
Protozoal cysts
Helminthic ova ( except in higher dose)
Viral agents ( HepA , Polio)