# Solutions and Precipitates

1. Dec 13, 2015

### Zoey Brown

1. The problem statement, all variables and given/known data
A solution of copper 2 sulphate is prepared by placing 5.80g of copper 2 sulphate in a flask and adding enough water to prepare 125 ml of solution. When a 25.0ml sample of this solution is added to 125ml of 0.125 mol/L sodium hydroxide a precipitate forms. Calculate the mass of the precipitate formed in the reaction.

2. Relevant equations
n=cv
m=nM

3. The attempt at a solution
The percipitate i found would be cu(OH)2 which would have the same mole as NaOH (n=cv) and then u would use the formula m=nM to find mass. The answer i got is 0.762g but i didnt use any info about the copper 2 sulphate, is this right?

2. Dec 13, 2015

### Staff: Mentor

You have to find what is the limiting reagent - it can be NaOH, it can be copper sulfate.

I find the question ambiguous - it doesn't say whether it is a copper sulfate pentahydrate (the most common form) or the anhydrous form.