Question

An aqueous KNO3 solution is made using 75.1 g of KNO3 diluted to a total solution volume of 1.95 L .Calculate the molarity of the solution. (assume a density of 1.05 g/mL for the solution)
Calculate the molality of the solution.
Calculate the mass percent of the solution.

Answer 1

Answer:

- $M=0.38M$

- $\\ \% m=3.67\%$

Explanation:

Hello,

In this case, since the molar mass of potassium nitrate is 101.1 g/mol, we can compute the molarity as follows:

$M=\frac{75.1g*\frac{1mol}{101.1g} }{1.95L} \\\\M=0.38M$

Moreover, as the mass percent is computed as:

$\% m=\frac{m_{KNO_3}}{m_{solution}} *100\%$

Thus, by using the given density of the solution, we obtain:

$\% m=\frac{75.1g}{1.95L*\frac{1000mL}{1L}*\frac{1.05g}{1mL} } *100\%\\\\ \% m=3.67\%$

Regards.