Question

a solution was prepared by dissolving 105.0 g of kcl in 215 g of water. what is the mole fraction of kcl in this solution? hint: the formula weight of kcl is 74.6 g/mol. hint: the molecular weight of water is 18.0 g/mol. round your answer to two places past the decimal. answer numeric 1 point 29 a solution was prepared by dissolving 105.0 g of kcl in 215 g of water.

Explanation:

Step1: Calculate moles of KCl

Use the formula $n=\frac{m}{M}$, where $n$ is moles, $m$ is mass and $M$ is molar - mass. For KCl, $m = 105.0$ g and $M=74.6$ g/mol. So, $n_{KCl}=\frac{105.0}{74.6}\approx1.41$ mol.

Step2: Calculate moles of water

For water, $m = 215$ g and $M = 18.0$ g/mol. Using $n=\frac{m}{M}$, we get $n_{H_2O}=\frac{215}{18.0}\approx11.94$ mol.

Step3: Calculate mole fraction of KCl

The mole - fraction formula is $x_{KCl}=\frac{n_{KCl}}{n_{KCl}+n_{H_2O}}$. Substitute $n_{KCl}=1.41$ mol and $n_{H_2O}=11.94$ mol. So, $x_{KCl}=\frac{1.41}{1.41 + 11.94}=\frac{1.41}{13.35}\approx0.10$.

Answer:

0.10