Answer:
[tex]\large \boxed{\text{0.180 mol/kg }}[/tex]
Explanation:
Assume 100 g of solution.
Then you have 10.0 g of NaCl and 90.0 g of water.
[tex]\text{Molal concentration} = \dfrac{\text{moles of solute}}{\text{kilograms of solvent}}[/tex]
1. Moles of NaCl
[tex]\text{Moles of NaCl} = \text{10.0 g NaCl} \times \dfrac{\text{1 mol NaCl}}{\text{58.44 g NaCl}} = \text{0.1711 mol NaCl}[/tex]
2. Kilograms of water
[tex]\text{Kilograms} = \text{90.0 g} \times \dfrac{\text{1 kg}}{\text{1000 g}} = \text{0.0900 kg}[/tex]
3. Molal concentration
[tex]\text{Molal concentration} = \dfrac{\text{0.1711 mol}} {\text{0.0900 kg}} = \textbf{1.90 mol/kg}\\\\\text{The molal concentration of the solution is $\large \boxed{\textbf{0.180 mol/kg }}$}[/tex]
