6 The volume of a sample of pure HCl gas was 189 ml at 25°C and 108 torr. It was completely dissolved in about 60 ml of water and titrated with a NaOH solution; 15.7 ml of the NaOH solution were required to neutralize the HCl. Calculate the molarity of the NaOH solution.

5-114 Carbon dioxide gas, saturated with water vapor, can be produced by the addition of aqueous acid to calcium carbonate based on the following balanced net ionic equation: (a) How many moles of wet CO (g), collected at 60.°C and 774 torr total pressure, are produced by the complete reaction of 10.0 g of CaCO3 with excess acid? (b) What volume does this wet CO2 occupy? (c) What volume would the CO2 occupy at 774 torr if a desiccant (a chemical drying agent) were added to remove the water? The vapor pressure of water at 60.°C is 149.4 mm Hg.

93 The complete combustion of octane can be used as a model for the burning of gasoline: 2C8H18+25O216CO2+18H2O Assuming that this equation provides a reasonable model of the actual combustion process, what volume of air at 1.0 atm and 25°C must be taken into an engine to burn 1 gallon of gasoline? (The partial pressure of oxygen in air is 0.21 atm and the density of liquid octane is 0.70 g/mL.)

Many nitrate salts can be decomposed by heating. For example, blue, anhydrous copper(II) nitrate produces the gases nitrogen dioxide and oxygen when heated. In the laboratory, you find that a sample of this salt produced a 0.195-g mixture of gaseous NO2 and O2 with a total pressure of 725 mm Hg at 35 C in a 125-mL flask (and black, solid CuO was left as a residue). What is the average molar mass of the gas mixture? What are the mole fractions of NO2 and O2 in the mixture? What amount of each gas b in the mixture? Do these amounts reflect the relative amounts of NO2 and O2 expected based on the balanced equation? Is it possible that the fact that some NO2 molecules combine to give N2O4 plays a role? Heating copper(II) nitrate produces nitrogen dioxide and oxygen gas and leaves a residue of copper(ll) oxide.

5-107 If 60.0 g of NH3 occupies 35.1 L under a pressure of 77.2 in. Hg, what is the temperature of the gas, in °C?

A person exhales about 5.8 102 L of carbon dioxide per day (at STP). The carbon dioxide exhaled by an astronaut is absorbed from the air of a space capsule by reaction with lithium hydroxide, LiOH. 2LiOH(s)+CO2(g)Li2CO3(s)+H2O(l) How many grams of lithium hydroxide are required per astronaut per day?

In the Mthode Champenoise, grape juice is fermented in a wine bottle to produce sparkling wine. The reaction is C6H12O6(aq)2C2H5OH(aq)+2CO2(g) Fermentation of 750. mL grape juice (density = 1.0 g/cm3) is allowed to take place in a bottle with a total volume of 825 mL until 12% by volume is ethanol (C2H5OH). Assuming that the CO2 is insoluble in H2O (actually, a wrong assumption), what would be the pressure of CO2 inside the wine bottle at 25C? (The density of ethanol is 0.79 g/cm3.)

A 19.9-mL volume of a hydrochloric acid solution reacts completely with a solid sample of magnesium carbonate, producing 183 mL of CO2 that is collected over water at 24.0C and 738 torr total pressure. The reaction is 2HCl(aq)+MgCO3(s)CO2(g)+H2O(l)+MgCl2(aq) What is the molarity of the HCl solution?

A mixture contained zinc sulfide, ZnS, and lead sulfide, PbS. A sample of the mixture weighing 6.12 g was reacted with an excess of hydrochloric acid. The reactions are ZnS(s)+2HCL(aq)ZnCl2(aq)+H2S(g)PbS(s)+2HCL(aq)PbCl2(aq)+H2S(g) If the sample reacted completely and produced 1.049 L of hydrogen sulfide, H2S, at 23C and 762 mmHg, what were the percentages of ZnS and PbS in the mixture?

A chemist weighed out 5.14 g of a mixture containing unknown amounts of BaO(s) and CaO(s) and placed the sample in a 1.50-L flask containing CO2(g) at 30.0C and 750. torr. After the reaction to form BaCO3(s) and CaCO3(s) was completed, the pressure of CO2(g) remaining was 230. torr. Calculate the mass percentages of CaO(s) and BaO(s) in the mixture.