Question

How many moles of MgCl2, are in 400. L of a 0.021 M solution?

A 0.75 mol
B 8.4 mol
C 7.5 mol
D 0.84 mol

Answer 1

The correct answer to the following question will be Option B "8.4 mol".

Step-by-step explanation:

The given values are:

Molarity of a solution = 0.021 M

Litres of solution = 400 L

Let the moles be "x".

As we know,

⇒
`Molarity = (Moles \ of \ solute)/(Litres \ of \ solution)`

On putting the estimated values, we get

⇒
`0.021=(x)/(400)`

On applying cross-multiplication, we get

⇒
`x =0.021* 400`

⇒
`x=8.4 \ mol`