Question

What is the mass of solute in a 500 mL solution of 0.200 M sodium phosphate (Na3PO4)? (MW Na3PO4 =164.0 g/mol)_____ g. Your answer should be rounded to the nearest tenth. Do not include units in your answer.

Answer 1

The mass of solute : 16.4

Further explanation

Molarity is a way to express the concentration of the solution

Molarity shows the number of moles of solute in every 1 liter of solute or mmol in each ml of solution

$\large{\boxed {\bold {M ~ = ~ \frac {n} {V}}}$

Where

M = Molarity

n = number of moles of solute

V = Volume of solution

mol Na₃PO₄

$\tt mol=M\times V=0.2\times 0.5=0.1$

mass Na₃PO₄

$\tt mass=mol\times MW\\\\mass=0.1\times 164=16.4$