Question

A scientist has 400 ml of an 8% solution. How much water needs to be added to reduce this to a 2% solution?

Answer 1

1200 ml

Step-by-step explanation:

Reducing the concentration to 2% means adding more water to dilute more solutes.

The relationship to apply is : c₁v₁=c₂v₂ where c is concentration and v is volume.

Given that

400 ml = v₁

0.08= c₁

0.02=c₂

v₂=?----find volume 2

400*0.08 =v₂*0.02

v₂=1600 ml

This means

400*0.08 =1600*0.02

Amount to be added to 400 ml to reach 1600 ml will be: 1600-400=1200 ml