Name______
Date______Per______
Molarity/Solubility Review Sheet
1)What is the definition and unit for molarity?
Molarity is the measure of a solutions concentration; molarity is the moles of solute per liter of solution.
2)What is the molarity of a solution made with 3 moles of solute in 4.5 liters of solution?
M = molM = 3 molesM = 0.67M
L 4.5 Liters
3)Calculate the molarity of a solution made by adding 2.5 grams of sodium hydroxide (NaOH) to 15 liters of water.
2.5 g x 1 mol = 0.0625 molM = mol M = 0.0625 molM = 0.0042 M
40 g L 15 Liters
4)How many grams of NaNO3 are needed to make 17 liters of 1.8 M solution?
mol = M x L30.6 mol x 85 grams = 2,601 grams
mol = 1.8 x 17 1 mol
mol = 30.6 mol
5)How many liters of water should be added to 11.7 grams of lithium bromide to make a 0.10M solution? Lithium Bromide is LiBr
11.7 g x 1mol = 0.134 molL = molL = 0.134L = 1.34 L
86.8 g M 0.10
6)What is the molarity of a solution made of 2 moles of CaCl2 in 250 liters of water?
M = molM = 2 molesM = 0.008 M
L 250 Liters
7)Calculate the molarity of a solution that is composed of 17.9 grams methanol (CH3OH) in 51.3 liters of water.
17.9 g x 1 mol = 0.559 molM = molM = 0.559 molM = 0.011 M
32 g L 51.3 L
8)How many grams of MgBr should be added to 3190 L of water to make a 1.2 molar solution?
mol = M x L3,828 mol x 104.2 g = 398,877 grams
mol = 1.2 x 3190 1 mol
mol = 3,828 mol
9)Define the following
- Solute the substance that dissolves in a solution
- Solvent the substance that does the dissolving in a solution
- Solution a homogeneous mixture made of a solute dissolved in a solvent
10)Define the following
- Saturated a solution that has dissolved all it can hold at a given temperature
- Unsaturated a solution that can still dissolve more solute at a given temperature
- Supersaturated a solution that has dissolved more solute than it should theoretically hold; requires both heating and stirring
11)What is the relationship between the solubility of a solid in a liquid and the temperature of the liquid?
The solubility of a solid in a liquid increases as the temperature increases.
12)What is the relationship between the solubility of a gas in a liquid and the temperature of the liquid?
The solubility of a gas in a liquid decreases as the temperature increases.
Using the above solubility curve, answer the following questions.
13)What is the maximum number of grams of KBr that can be dissolved in 100 g of water at a temperature of 50oC?
about 83 grams
14)If water at 30oC contained 100 g of NaNO3, how would that solution be classified? (hint: use review question 10)
It would be supersaturated because it should only hold about 90 grams.
15)What is the maximum number of grams of KNO3 that can be dissolved in 75 g of water at a temperature of 70oC? (**Note the amount of water)
120 g KNO3 = ? g KNO3 120 x 75 / 100 = 90 g KNO3
100 g H2O 75 g H2O
16)If you had 100 grams of KBr in 100 grams of water, what would the temperature have to be in order to have a saturated solution?
80ºC
17)Which substance has the greatest solubility at a temperature of 80oC?
KNO3
18)How many grams of NH4Cl must be added to 100 grams of water at a temperature of 40oC in order to create a saturated solution?
about 42 grams