WORKSHEET Mole Fraction

Transcription

1 NAME: DATE: PERIOD: WORKSHEET Mole Fraction 1. What is the mole fraction of sodium chloride in a solution containing 0.23 moles of NaCl and 5.5 moles of water? 2. What is the mole fraction of oxygen in a gaseous mixture containing 25 grams of oxygen, 15 grams of nitrogen, and 10 grams of helium? R1. The following information was obtained in the laboratory. Determine the density of the object involved. Pre-AP Notes 2-6 Description of Measurement Mass of object Volume of water in graduated cylinder Volume of water in cylinder after object is added Value g 52.5 ml 63.2 ml

2 NAME: DATE: PERIOD: AP CHEMISTRY WORKSHEET Concentration of Ions in Solution 1. Determine the concentration of each ion in the following solutions: 2.22 M Li2SO M (NH4)3PO M Cr(NO3)6 2. What is the molarity of a solution that contains g of KMnO4 dissolved to make 15.0 ml of solution? ml of M Na3PO4 is mixed with 200. ml of M Li2CrO4. What is the concentration of all ions in the solution? 4. If 25.0 ml of 1.0 M (NH4)2CO3 is mixed with 25.0 ml of 0.75 M (NH4)2CO3, what is the resulting concentration of the solution?

3 NAME: DATE: PERIOD: WORKSHEET The Preparation of Solutions by Dilution 1. How would you prepare 1500 ml of a 0.50 M solution of KI from a stock solution which is 2.25 M in concentration? 2. How many milliliters of 0.25 M H2SO4 can be prepared from 57 ml of a 3.0 M solution of H2SO4? ml of a 0.50 M solution of KMnO4 is added to 100. ml of water. What is the molarity of the resulting solution? AP1. How many milliliters of 11.6-molar HCl must be diluted to obtain 1.0 liter of 3.0-molar HCl? a. 3.0 ml b. 35 ml c. 260 ml d. 3,900 ml e. 1,000 ml R1. How many atoms of carbon are in 2.23 grams of propane (C3H8)? Pre-AP Notes 3-4 R2. What is the percent composition of PbSO4? Pre-AP Notes 3-6

4 NAME: DATE: PERIOD: WORKSHEET Limiting Reagents Revisited grams of nitrogen are reacted with 12.0 grams of hydrogen according to the following equation: Determine the limiting reagent: N2 + 3H2 2 NH3 Determine the mass of ammonia produced: Determine the mass of excess reagent that remains after the reaction grams of phosphorus are reacted with 15.0 grams of chlorine gas according to the following equation: 2P + 5Cl2 2PCl5 Determine the limiting reagent: Determine the mass of phosphorus pentachloride produced: Determine the mass of excess reagent that remains after the reaction.

5 NAME: DATE: PERIOD: AP CHEMISTRY WORKSHEET Solution Stoichiometry 1. Calculate the number of grams of carbon dioxide, CO2, that can react with 135 ml of a M solution of potassium hydroxide, KOH, according to the following reaction: 2KOH + CO2 K2CO3 + H2O 2. What volume of M HNO3 solution is required to react completely with 38.6 ml of M Ba(OH)2? Ba(OH)2 + 2HNO3 Ba(NO3)2 + 2H2O 4. An excess of AgNO3 reacts with ml of an AlCl3 solution to give g of AgCl. What is the concentration, in moles per liter, of the AlCl3 solution? AlCl3 + 3AgNO3 3AgCl + Al(NO3) AP1. What volume of molar HCl is required to neutralize 25.0 milliliters of molar Ba(OH)2? a ml b ml c ml d ml e ml AP2. A student wishes to prepare 2.00 L of molar KIO3 (molecular weight 214). The proper procedure is to weigh out : a g of KIO3 and add 2.0 kilograms of H2O b g of KIO3 and add H2O until the final homogeneous solution has a volume of 2.00 liters c g of KIO3 and add H2O until the final homogeneous solution has a volume of 2.00 liters d g of KIO3 and add 2.00 liters of H2O e g of KIO3 and add 2.00 liters of H2O

6 NAME: DATE: PERIOD: AP CHEMISTRY WORKSHEET Gravimetric Analysis 1. Calculate the percent purity of a sample of Mg(OH)2 if titration of g of the sample required ml of M H3PO4. 3Mg(OH)2 + 2H3PO4 Mg3(PO4)2 + 6H2O 2. A 2.00g sample of limestone was dissolved in hydrochloric acid and all the calcium present in the sample was converted to Ca 2+ (aq). Excess ammonium oxalate solution, (NH4)2C2O4(aq), was added to the solution to precipitate the calcium ions as calcium oxalate, CaC2O4(s). The precipitate was filtered, dried and weighed to a constant mass of 2.43g. Determine the percentage by mass of calcium in the limestone sample.

7 R1. Use the data below to: Pre-AP Notes 3-8 A. fill in the missing mass of water in the table B. find the formula of the hydrate SUBSTANCE Cu(NO 3) 2 XH 2O before heating Cu(NO 3) 2 after heating H 2O which evaporated MASS 5.00 grams 3.90 grams R2. A component of protein called serine has an approximate molar mass of 100 g/mole. If the percent composition is as follows, what are the empirical and molecular formulas of serine? Pre-AP Notes 6-6 C = % H= % O = % N= %