Question

The solubility of sodium chloride (NaCl) in water is 36.2 g NaCl per 100 g water at 25°C. Which describes a solution of 29.5 g NaCl in 75.0 g water at 25°C?

an unsaturated solution


a saturated solution with all sodium chloride dissolved


a supersaturated solution


a saturated solution with excess sodium chloride undissolved

Answer 1

Answer:

A saturated solution with excess sodium chloride undissolved

Explanation:

Hello,

In this case, since 32.6 g of sodium chloride are completely dissolved in 100 g of water at 25 °C, we can propose a rule of three to compute the grams of sodium chloride which are completely dissolved but in 75.0 g of water as shown below:

$36.2g\rightarrow 100g\\X\rightarrow 75.0g\\\\X=\frac{75.0g*36.2g}{100g}=27.15g$

For that reason, since 29.5 g of sodium chloride are attempted to be dissolved, the following amount will remain undissolved:

$m_{undissolved}=29.5g-27.15g=2.35g$

Thus, since the undissolved amount is low we can conclude it is a saturated solution with excess sodium chloride undissolved since 2.35 g will remain undissolved.

Best regards.