Question

A solution contains 10 g of KNO3 per 100 g of water at 30˚C. Is the solution unsaturated, saturated or supersaturated?

Answer 1

A solution containing 10 g of KNO3 per 100 g of water at 30°C is unsaturated because it contains less than the maximum amount of solute (48 g) that can be dissolved at that temperature.

Step-by-step explanation:

Based on the information provided, a solution containing 10 g of KNO3 per 100 g of water at 30°C would need to be compared to the known solubility at that temperature to determine if it is unsaturated, saturated, or supersaturated. The solubility curve indicates that at 30°C, approximately 48 g of KNO3 can dissolve in 100 g of water. Since 10 g of KNO3 is less than the maximum solubility at this temperature, the solution is unsaturated.

Answer 2

Explanation: As you can see, potassium nitrate has s solubility of about

67 g / 100g H

2

O

at

40

∘

C

. This means that at

40

∘

C

, a saturated potassium nitrate solution will contain

67 g

of dissolved salt for every

10 0g

of water.

You know that at this temperature, your solution contains

35 g

of potassium nitrate in

100 g

of water. This solution will be unsaturated because it contains less potassium nitrate than the maximum amount that can be dissolved.

In order to make a saturated solution, you must get the total mass of potassium nitrate to

67 g

, which means that you must add

mass of KNO

3

a

to be added

=

67 g

−

35 g

=

∣

∣

∣

∣

¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

a

a

32 g

a

a

∣

∣

−−−−−−−−