1.12    If the density of methanol is 0.793 kg L–1, what is its volume needed for making 2.5 L of its 0.25 M solution?

Answers (1)
D Divya Prakash Singh

Given that the density of methanol CH_{3}OH is 0.793 Kg\ L^{-1}.

So, the number of moles present in the methanol per litre will be or the Molarity of the solution will be : 

= \frac{0.793Kg\ L^{-1}}{0.032Kg\ mol^{-1}} = 24.78\ mol\ L^{-1}

Now, to make 2.5L of its 0.25M solution:

We will apply the formula: M_{1}V_{1} (for\ given\ solution) = M_{2}V_{2} (for\ solution\ to\ be\ prepared)

24.78\times V_{1} =0.25\times 2.5L

V_{1} = 0.02522L\ or\ 25.22\ mL.

Hence 25.22\ mL volume will be required for making  2.5L of methanol 0.25M solution.