The carbon dioxide exhaled in the breath of astronauts is often removed from the spacecraft by reaction with lithium hydroxide 2LiOH(s)+CO2(g)Li2CO3(s)+H2O(l) Estimate the grams of lithium hydroxide required per astronaut per day. Assume that each astronaut requires 2.50 103 kcal of energy per day. Further assume that this energy can be equated to the heat of combustion of a quantity of glucose, C6H12O6, to CO2(g) and H2O(l). From the amount of glucose required to give 2.50 103 kcal of heat, calculate the amount of CO2 produced and hence the amount of LiOH required. The H for glucose(s) is 1273 kJ/mol.

list at least three quantities that must be conserved in chemical reactions.

In a common experiment in the general chemistry laboratory, magnesium metal is heated in air to produce MgO. MgO is a white solid, but in these experiments it often looks gray, due to small amounts of Mg3N2, a compound formed as some of the magnesium reacts with nitrogen. Write a balanced equation for each reaction.

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.

Table 6.1 lists some clues that a chemical reaction has occurred. However, these events do not necessarily prove the existence of a chemical change. Give an example for each of the clues that is not a chemical reaction but a physical change.

Write the balanced chemical equation for the complete combustion of adipic acid, an organic acid containing 49.31% C, 6.90% H, and the remainder O, by mass.

Consider the following particulate-level representation of a chemical equation: The white spheres represent hydrogen atoms, the black sphere represents a carbon atom, and the red spheres represent oxygen atoms. a Write a balanced chemical equation representing this reaction. b Write a word description of the reaction on the particulate and molar levels.

Balance each of the following equations, and then write the net ionic equation. Show states for all reactants and products (s, . g, aq). (a) the reaction of sodium hydroxide and iron(II) chloride to give iron(II) hydroxide and sodium chloride (b) the reaction of barium chloride with sodium carbonate to give barium carbonate and sodium chloride (c) the reaction of ammonia with phosphoric acid

Polychlorinated biphenyls (PCBs) have been used extensively as dielectric materials in electrical transformers. Because PCBs have been shown to be potentially harmful, analysis for their presence in the environment has become very important. PCBs are manufactured according to the following generic reaction: C12H10+nCl2C12H10nCln.+nHCl This reaction results in a mixture of PCB products. The mixture is analyzed by decomposing the PCBs and then precipitating the resulting Cl asAgCl. a. Develop a general equation that relates the average value of n to the mass of a given mixture of PCBs and the mass of AgCl produced. b. A 0.1947-g sample of a commercial PCB yielded 0.4791 g of AgCl. What is the average value of n for this sample?