How much bleaching powder (having 20% available chlorine) is needed to disinfect 10000 litres of water whose chlorine demand is $1.0 m g / l$ ? It should be ensured that, after about 1 hour contact time $0.2 m g / l$ chlorine is available.

40 g

No worries! We‘ve got your back. Try BYJU‘S free classes today!

30 g

No worries! We‘ve got your back. Try BYJU‘S free classes today!

48 g

No worries! We‘ve got your back. Try BYJU‘S free classes today!

68 g

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

Open in App

Solution

The correct option is D 68 g
Total dosage of chlorine $(m g / l)$
$= T o t a l d e m a n d (m g / l) + R e s i d u a l (m g / l) T o t a l d o s a g e = (1 + 0.2) m g / l = 1.2 m g / l$
For 10000 litre of water, chlorine required,
$= 1000 - l \times 1.2 m g / l = 12000 m g = 12 g$
This chlorine has to come from beaching powder which has 20% available chlorine
Hence, Bleaching powder required
$= \frac{12}{0.2} g = 60 g$

Note:
Since no answer is matching. We can take nearest as correct answer i.e., 68 g.

Suggest Corrections