Question

The solubility of potassium chloride is 34.2 g/100 g H2O at 20°C. A 68.4-g sample of potassium chloride is added to 200.0 g of water at 20°C. Is the solution saturated, unsaturated, or supersaturated?

supersaturated

saturated

unsaturated

Answer 1

Answer: The solution is saturated.

Step-by-step explanation:

We are given:

Solubility of KCl at 20°C = 34.2 g/100 g

We need to find the type of solution when 68.4 grams of KCl is added to 200 grams of water at 20°C.

There are three possibilities:

1. If concentration is equal to the solubility; it is considered as saturated solution.
2. If concentration is less than the solubility; it is considered as unsaturated solution.
3. If concentration is greater than the solubility; it is considered as supersaturated solution.

Ratio of the solubility of two solution is:

When 34.2 gram of KCl is dissolved in 100 grams, the ratio becomes:
`(34.2)/(100)`

When 68.4 gram of KCl is dissolved in 200 grams, the ratio becomes:
`(68.4)/(200)=(34.2)/(100)`

As, the ratio of the solubility of both the solutions is equal, which means that the solution is saturated.

Answer 2

Answer: saturated
The solubility of a substance will increases if more mass of the solvent used. It will also increase if the temperature higher. The sample is 68.4-g sample of potassium chloride in 200.0 g of water at 20°C. Then, the concentration would be
KCL mass/ H2O mass= 68.4g/200g= 34.2g/100g

The concentration is equal to solubility, so the solution is saturated