Chapter 3: Stoichiometry of Formulas and EquationsDifficulty: E97.a. A solution of common salt, NaCl, in water has a concentration of 0.0921 M. Calculatethe number of moles of NaCl contained in 50.0 mL of this solution.b. If, instead, an NaCl solution is prepared by dissolving 10.0 g of solid NaCl in enough water to make 250. mL of solution, what is the molarity?Ans:a. 0.00461 gb. 0.684 MDifficulty: E98.Aluminum metal dissolved in hydrochloric acid as follows:2Al(s) + 6HCl(aq) 2AlCl3(aq) + 3H2a. What is the minimum volume of 6.0 MHCl(aq) needed to completely dissolve 3.20 g of aluminum in this reaction?b. What mass of AlCl3 would be produced by complete reaction of 3.20 g of aluminum?(g)Ans:a. 59.3 mLb. 15.8 gDifficulty: M99.One mole of O2has a mass of 16.0 g.
Difficulty: E100.One mole of methane (CH4) contains a total of 3 1024atoms.
Difficulty: E101.The formula CH3O0.5is an example of an empirical formula.
Difficulty: E102.In combustion analysis, the carbon and hydrogen contents of a substance are determinedfrom the CO2and H2O, respectively, which are collected in the absorbers.
Difficulty: E103.In combustion analysis, the oxygen content of a substance is equal to the total oxygen inthe CO2and H2O collected in the absorbers.
Difficulty: M104.Constitutional (structural) isomers have the same empirical formula but different molecular formulas.
Difficulty: M105.Constitutional (structural) isomers have the same molecular formula but different structural formulas.
Difficulty: MPage 47