1. 63 g / 100 g H2O 50 g / 100 g H2O What is the solubility of potassium
nitrate at 40ºC? 
63 g / 100 g H2O
How many grams of potassium chloride are
needed to make a saturated solution at 80ºC?
50 g / 100 g H2O

2. What type of solution (saturated, unsaturated,
or supersaturated) is 32 g of NH4Cl in 60 g
of water at 50ºC?
32 = x
x = 53 g
The solubility at 50ºC is 50g so the solution is
supersaturated
What is the mass percentage of NH4Cl
at 10ºC?
33 g / 100 g H2O
(33 g / 133 g )x 100 = 25%

3. 47 = x 100 15 x = 7.1 g have 3 so need (7.1 – 3 ) = 4.1 g more.
A solution has a 3 g KClO3 in 15 g H2O at
50ºC. How many more grams dissolve at
90ºC?
47 = x
x = 7.1 g
have 3 so need (7.1 – 3 ) = 4.1 g more.

4. 15.0 g x 1 mole = 0.0438 mole 342.3 g 0.0438 mole = 0.219 M Al2(SO4)3
What is the molarity of 15.0 g of Al2(SO4)3 in
200. ml solution?
15.0 g x 1 mole = mole
342.3 g
mole = M Al2(SO4)3
0.200 L

5. 7. How many grams of Na2C2O4 are needed
to make 80.0 ml of 0.90 M solution?
0.90 mole/L x L = mole
0.072 mole x g = 9.6 g Na2C2O4
1 mole

6. How many grams of aluminum sulfate precipitate are made by the reaction of 60.0 ml of 0.54 M sodium sulfate solution with ml of M aluminum nitrate solution? Write the balanced equation and then show all work.
3 Na2 SO4 + 2 Al(NO3)3 → Al2(SO4)3 + 6 NaNO3

7. 3 Na2 SO4 + 2 Al(NO3)3 → Al2(SO4)3 + 6 NaNO3
Find moles of each reactant using:
molarity x volume (L) = moles
0.54 moles x L = moles Na2 SO4 L
0.080 moles x L = moles Al(NO3)3 L

8. 3 Na2 SO4 + 2 Al(NO3)3 → Al2(SO4)3 + 6 NaNO3
Next use mole ratios to find moles of product and grams of product.
3 Na2 SO4 = mole 3x = 0.032
1 Al2(SO4) X x = moles
2 Al(NO3)3 = x = moles
1 Al2(SO4) X Al2(SO4)3
moles x (342.3g) = 1.4 g Al2(SO4)3
1 mole