Question

A student mixes 20.0 g of a salt in 100.0 g of water at 20 oC and obtains a homogeneous solution. Which salt could this be and why? The solubility of KCl at 20 oC in 100.0 g of water is 10.0 g and the solubility of KNO3 at 20 oC in 100.0 g of water is 30.0 g. Question 2 options: 1) KCl because it is saturated. 2) KCl because it is unsaturated. 3) KNO3 because it is saturated. 4) KNO3 because it is unsaturated.

Answer 1

4) KNO₃ because is unsaturated.

Step-by-step explanation:

The solubility of KCl in water at 20°C is 10.0g/100,0g and of KNO₃ is 30.0g/100.0g.

When you make a solution under these concentrations, the solutions will be saturated, higher concentrations gives heterogeneous solutions. Lowers concentrations gives homogeneous solutions.

As concentration of the solution made for the student is 20.0g / 100.0g:

If the solution is of KCl produce a heterogeneous solution because is oversaturated.

If the solution is of KNO₃ produce a homogenous solution because is unsaturated.

Thus, the solution is made of 4) KNO₃ because is unsaturated.