Molarity Worksheet
Name______Period_____
1. Calculate the molarity of :
a. 3.5 moles of NaNO3 in 4 liters of solution
b. 4.8 moles of NaOH in 3400 mls of solution
c. 6.5 moles of HCl in 34 mls of solution
d. 30.9 grams of NaOH in 400 mls of solution
e. 450 grams of K2CrO4 in 340 mls of solution
f. 340 grams of Na2CO3 in 2 liters of solution.
2. Calculate the moles in each of the following solutions:
a. 2.6 Liters of .5M HCl
b. 3.9 mls of .309 M NaNO3
c. 57 Liters of 12 M H2SO4
3. Calculate the grams in each of the following solutions.
a. 7.3 Liters of 3.6M Co(OH)2
b. 5.4 liters of 12 M HCl
c. 300 mls of 3.4 M NaNO3
d. 400 mls of .002M K2CrO4
e. 20 mls of 18 M H2SO4
4. Dilution Rule
a. Assuming you have a 12M HCl solution and you want to make 4.0 liters of 5.4M HCl, how would you go about this process?
b. How would you make 230 mls of .5M HCl from a stock solution of 12M HCl
c. Suppose you want to make 50 mls of .002M K2CrO4 solution from a 7.5 M stock solution, how would you go about this?
d. How would you make a 3.0 Liters of a .1M NaOH solution from a 6M stock solution?
Solubility as a function of Temperature.
Solubility(grams solute/100grms H2O)
Honors ChemistryName
Molality and %
Name______Period_____
%(mass/volume)= mass of solute/100 mls of solution
%(vol/vol)= volume of solute /100 mls of solution
molality= moles of solute /kilograms of solvent
mole fraction of solute= moles of solute/ total moles
mole fraction of solvent= moles of solvent/total moles
1. What is the % (mass/volume) of a solution made by adding 12.3 grams of NaCl in 300 mls of solution total?
2. What is the %(volume /volume) of a solution made by adding 12mls of alcohol to 340mls of water?
3. How many grams of MgSO4 are required to make 250 mls of solution that is 1.6% MgSO4?
4. A solution contains 2.7 grams of CuSO4 in 75 mls of solution. What is the percent(m/v) of the solution?
*extra credit 5. The density of a solution of sucrose is 1.5grams/milliliter. Describe how to make this solution and find the %(mass/volume) Water has a density of 1g/ml
6. Calculate the molality of a solution made by adding 34.8 grams of potassium sulfate to 800 grams of water.
7. Calculate the concentration of a solution composed of 13.1 grams of Barium Nitrate dissolved in 750 grams of water.
8. Calculate the molality of a solution containing 6.00 grams of sodium hydroxide dissolved in 325 grams of water.
9. Calculate the mole fraction of solute and solvent in a solution containing 83 grams of lithium bromide and 125 grams of water.
Honors Chemistry
Chapter 17Colligative Properties
Name______Period_____
Colligative properties: physical properties of a solution that depend upon the amount of solute in the solvent.
a. Vapor Pressure Lowering: Some solutes attract the water molecules so the vapor pressure is lowered. The more solute, the lower the VP
Vapor Pressure New= X solvent (Vapor Pressure puresolvent)
where X is mole fraction
b. Boiling Point Elevation: Since Boiling Point is dependent of VP, and a solute lowers the VP, then the Boiling Point increases.
^Tb= kb x m for ionic solutions ^Tb= kb x m x i
kb= freezing point constant for solvent. Water is .512oC/m see text for more
i= number of ions formed when an ionic compound dissociates.
NaCl---> Na+ + Cl- i= 2
m= molality
c. Freezing Point Lowering: A solute in a solvent interfers with crystal structure so the solvent freezes at a lower temperature.
all equations are analogous to ^Tb.
Kf for water is 1.86oC/m
d. Osmotic Pressure is a increased by a solute in a solvent.
Problems:
1. Calculate the boiling temperature for a solution which contains 1.5mole of sodium iodide, NaI, dissolved in 1.25 kg of water.
2. Calculate the freezing point of a solution composed of 23.4 grams of Calcium Fluoride dissolved in 175 grams of water.
3. Calculate the molality of an aqueous (not ionic), that has a boiling point of 105.0oC.
4. At what temperature will a 3.0m solution of sodium fluoride freeze?
5. Calculate the boiling temperature for a solution which contains .325 mole of calcium phosphate dissolved into 240.0 grams of water.
6. What is the value of i for the following solutes?
a. Na2SO4b. KOHc. Al2(SO4)3d. CH3OH
7. A solution is made by dissolving 25.0 grams of sodium sulfate in .500 kg of water. What are the boiling and freezing points of this solution?
8. What is the GFM of a substance that lowers the freezing point of water by 1.12o when 20 grams are put into 200 grams of water. ( not ionic)
9. What is the GFM of a substance that raises the boiling point to 103oC when 3.5 grams are put into 150 grams of water? ( not ionic )