The volume required : 0.2 L
Further explanation
Given
500ml of 0.1M potassium dichromate (vii)
0.25 solution
Required
The volume
Solution
We can use dilution formula :
M₁V₁=M₂V₂
M₁ = 0.25
M₂ = 0.1
V₂ = 500 ml = 0.5 L
The initial volume taken :
V₁=(M₂V₂)/M₁
V₁=(0.1 x 0.5)/0.25
V₁=0.2 L