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

A saturated solution with excess sodium chloride undissolved

Step-by-step 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=(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.