4.8 In an experiment carried out at very low pressure, 13x1015 molecules of H2 are reacted with acetylene, C2H2, to form ethane, C2H6, on the surface of a catalyst. Write a balanced chemical equation for this reaction. How many molecules of acetylene are consumed?

The sugar sucrose, which is present in many fruits and vegetables, reacts in the presence of certain yeast enzymes to produce ethanol and carbon dioxide gas. Balance the following equation for this reaction of sucrose. C12H22O11(aq) + H2O(l) C2H5OH(aq) + CO2(g)

Propane, C3H8, is the fuel of choice in a gas barbecue. When burning, the balanced equation is C3H8+5O23CO2+4H2O a What is the limiting reactant in cooking with a gas grill? b If the grill will not light and you know that you have an ample flow of propane to the burner, what is the limiting reactant? c When using a gas grill you can sometimes turn the gas up to the point at which the flame becomes yellow and smokey. In terms of the chemical reaction, what is happening?

4.108 Elemental analysis is sometimes carried out by combustion of the sample. For a hydrocarbon, the only products formed are CO2 and H2O. If a 1.36-g sample of an unknown hydrocarbon is burned and 2.21 g of H2O is produced along with 4.07 g of CO2, what is the empirical formula of the hydrocarbon?

Nitric acid is produced commercially by the Ostwald process, represented by the following equations: 4NH3(g)+5O24NO(g)+6H2O(g)2NO(g)+O2(g)2NO2(g)3NO2(g)+H2O(l)2HNO3(aq)+NO(g) What mass of NH3 must be used to produce 1.0 106 kg HNO3 by the Ostwald process? Assume 100% yield in each reaction, and assume that the NO produced in the third step is not recycled.

4.12 In petroleum refining, hydrocarbons are often manipulated by reacting them with H2(g). If hexene, C6H12, is reacted with hydrogen to form hexane, C6H14, how many moles of hydrogen are needed to react with 453 moles of hexene?

(a) Butane gas, C4H10, can burn completely in air [use O2(g) as the other reactant] to give carbon dioxide gas and water vapor. Write a balanced equation for this combustion reaction. (b) Write a balanced chemical equation for the complete combustion of C3H7BO3, a gasoline additive. The products of combustion are CO2(g), H2O(g), and B2O3(s).

Calcium carbonate forms carbon dioxide and calcium oxide when it is heated above 900 °C in a limekiln. When heated to 1000 °C in a laboratory, 4.31 g calcium carbonate produces 2.40 g calcium oxide and 1.90 g carbon dioxide. Outline a method similar to combustion analysis by which you could determine the empirical formula for calcium carbonate from these data. Carry out the determination.

Ethanol, C2H5OH, is a gasoline additive that can be produced by fermentation of glucose. C6H12O62C2H5OH+2CO2 (a) Calculate the mass (g) of ethanol produced by the fermentation of 1.000 lb glucose. (b) Gasohol is a mixture of 10.00 mL ethanol per 90.00 mL gasoline. Calculate the mass (in g) of glucose required to produce the ethanol in 1.00 gal gasohol. Density of ethanol = 0.785 g/mL. (c) By 2022, the U. S. Energy Independence and Security Act calls for annual production of 3.6 1010 gal of ethanol, no more than 40% of it produced by fermentation of corn. Fermentation of 1 ton (2.2 103 lb) of corn yields approximately 106 gal of ethanol. The average corn yield in the United States is about 2.1 105 lb per 1.0 105 m2. Calculate the acreage (in m2) required to raise corn solely for ethanol production in 2022 in the United States.