Question

What is the mass of solute in 500mL solution of 0.200M sodium phosphate (Na3PO4: M.W. 164.0)?

Answer 1

16.4g of solute is present in 500mL of the solution.

Step-by-step explanation:

Given:

Volume of solution, V = 500mL = 0.5L

Molarity of Sodium phosphate, M = 0.2M

Molecular weight of Na₃PO₄ = 164 g/mol

Mass of the solute, m = ?

We know:

`Molarity = (moles of the solute)/(Volume of solution in litres)`

And

Number of moles =
`(mass of the solute)/(molecular weight)`

On substituting the value we get:

`0.2 = (m)/(164) X (1)/(0.5) \\\\m = 0.2 X 164 X 0.5\\\\m = 16.4 g`

Therefore, 16.4g of solute is present in 500mL of the solution.