AP CHEMISTRY NOTES 1-1 MOLE FRACTION
Mole Fraction (X) – the number of moles of a substance per total moles of a mixture
Mole Fraction = ______Moles A______Moles A + Moles B + . . .
EXAMPLE: Determine the mole fraction of iodine in a mixture of 0.23 moles of I2 mixed with 1.1 moles of carbon tetrachloride (CCl4).
EXAMPLE: A canister contains 2.3 g of PCl5, 1.2 g of PCl3, and 0.75 g of Cl2. Determine the mole fraction of each of these gases.
AP CHEMISTRY NOTES 1-2 THE CONCENTRATION OF IONS IN SOLUTION
REVIEW EXAMPLE: Determine the molarity of a solution that contains 1.22 g of KI dissolved in water to make 250. mL of solution.
EXAMPLE: Determine the concentration of each ion in the following solutions:
0.25 M BaCl2 ______
1.5 M Cr(OH)3 ______
0.11 M K3PO4 ______
EXAMPLE: 100. mL of 0.50 M K2SO4 is mixed with 75.0 mL of 0.25 M Al(NO3)3. What is the concentration of each ion in the solution?
EXAMPLE: 50. mL of 0.125 M FeCl3 is mixed with 25 mL of 0.220 M FeCl3. What is the resulting molarity of the solution?
AP CHEMISTRY NOTES 1-3 THE PREPARATION OF SOLUTIONS BY DILUTION
To Prepare a Solution by Dilution:
M1 V1 = M2 V2 (stock soln) (new soln)
EXAMPLE: How would you prepare 100.0 mL of a 0.40 M solution of MgSO4 from a stock solution that is 2.0 M in concentration?
EXAMPLE: How much water would you add to 25 mL of 1.00 M NaOH to prepare a 0.75 M solution?
AP CHEMISTRY NOTES 1-4 LIMITING REAGENTS REVISITED
EXAMPLE: 20.0 grams of propane are reacted with 50.0 grams of oxygen at STP according to the following reaction:
C3H8 + 5O2 → 3CO2 + 4H2O
Determine the limiting reagent:
Determine the mass of carbon dioxide produced:
Determine the mass of excess reagent that remains after the reaction.
AP CHEMISTRY NOTES 1-5 STOICHIOMETRY OF SOLUTIONS
EXAMPLE: Calculate the volume of 12 M HCl that just reacts with 15 g of aluminum.
EXAMPLE: What is the molarity of a solution of sodium hydroxide, NaOH, if 36.9 mL of this solution is required to react with 29.2 mL of 0.101 M hydrochloric acid solution according to the following reaction?
______HCl + NaOH > NaCl + H2O
AP CHEMISTRY NOTES 1-6 GRAVIMETRIC ANALYSIS
EXAMPLE: An impure sample of solid Na2CO3 is allowed to react with 0.1755 M HCl.
______Na2CO3 + 2HCl > 2NaCl + CO2 + H2O
A 0.2337-g sample of sodium carbonate requires 15.55 mL of HCl solution to react completely. What is the purity of the sodium carbonate?
EXAMPLE: When a sample of impure potassium chloride (0.4500g) was dissolved in water and treated with an excess of silver nitrate, 0.8402 g of silver chloride was precipitated. Calculate the percentage KCl in the original sample.
AP CURRICULUM FRAMEWORK Unit 1