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

Answer:

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

∣

∣

−−−−−−−−