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.

1. Sometimes a reaction can fall in more than one category. Into what category (or categories) does the reaction of Ba(OH)2(aq) + H+PO4(aq) fit? acid-base and oxidation-reduction oxidation-reduction acid-base and precipitation precipitation

4.22 Generally, an excess of O2 is needed for the reaction Sn+O2SnO2 . What is the minimum number of moles of oxygen required to oxidize 7.3 moles of tin?

Write balanced chemical equations for the following reactions: (a) zinc metal heated in a stream of oxygen gas (b) zinc carbonate heated until loss of mass stops (c) zinc carbonate added to a solution 0f acetic acid, CH3CO2H (d) zinc added to a solution of hydro-bromic acid

4.19 How many metric tons of carbon are required to react with 7.83 metric tons of Fe2O3 according to the following reaction? 2Fe2O3+3C3CO2+4Fe How many metric tons of iron are produced?

3.14 A number of compounds are used in cement, and reactions among them occur when water is added. In one, CaO reacts with Al2O3 and water to form Ca3Al2(OH)12. Write a bal- anced chemical equation for this process.

What is the mass of fish, in kilograms, that one would have to consume to obtain a fatal dose of mercury, if the fish contains 30 parts per million of mercury by weight? (Assume that all the mercury from the fish ends up as mercury (II) chloride in the body and that a fatal dose is 0.20 g of HgCl2.) How many pounds of fish is this?

4.48 Elemental phosphorous is used in the semiconductor industry. It can be obtained from an ore called fluoroapatite via reaction with SiO2 and C: 4Ca5( PO4)3F+18SiO2+30C3P4+30CO+18CaSiO3+2CaF2 Suppose a particular semiconductor production plant requires 1500 kg of P4. If the recovery of P4 from this reaction is 73% efficient, what mass of fluoroapatite is needed?

The balanced equation for the reduction of iron ore to the metal using CO is Fe2O3(s) + 3 CO(g) 2 Fe(s) + 3 CO2(g) (a) What is the maximum mass of iron, in grams, that can be obtained from 454 g (1.00 lb) of iron(III) oxide? (b) What mass of CO is required to react with 454 g cot Fe2O3?