Question

What is the concentration (M) of an aqueous methanol produced when 0.200 L of a 2.00 M solution was diluted to 0.800 L?

Answer 1

`M=0.5 M`

Explanation:

`M=(mol)/L`

Calculating moles before dilution:

`mol=M*L=2.0M*0.2L=0.4 mol`

The amount of moles stays the same, although we increase the volume. But we se from the formula `mol=M*L` that the molarity will change.

we know amount of moles, and liters:

`M=(0.4mol)/(0.8L)=0.5 M`