Dec 2017
2
0
Walnut Cove, NC
A colleague and I are lab partners and are having some issues with solubility. The book provided to us does not cover how to solve the problems we were given. This assignment was also not assigned in enough time to receive tutoring on the topic. Does anyone know the rules of solubility/saturation for problems like this?

The solubility of NaOH is 129 g NaOH/100 g water at 40°C. If a solution contains 70 g NaOH in 50 g of water at 40°C, is the solution saturated or unsaturated?
 
May 2017
94
0
thailand
so ...we are told the normal solubility of NaOH is 129 in 100 g of water (@40C) this is the most you can normally get to dissolve.

If 70g of NaOH is in 50g , then this is the same concentration as 140g in 100 g

But we have been told 129 is the normal solubility , so we have MORE dissolved in, than normal for 40C

This can sometimes happen if the solution is heated it will dissolve more , when cooled slowly to 40C, the excess does not always separate out

It is saturated

The correct term is Super Saturated