Question

A saline solution contains 0.90 g NaCl in exactly 100. mL of solution. What is the molarity of the solution ?

Answer 1

$C_m= \frac{m}{M \cdot V}$

C_m - molarity or molar concentration of the solution

m - mass of the solute, g

M - molar mass of the solute, g/mol

V - volume of the solution, L

$M(NaCl)=1 \cdot 22.99 + 1 \cdot 35.453 = 58.443 \; g/mol$

$C_m= \frac{0.9}{58.443 \cdot 0.1} \approx 0.15 \; M$

Answer: 0.15 M.