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a. How many kilojoules are released when 75.0 g of
b. How many kilojoules are absorbed when 315 g of
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Basic Chemistry
- 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.arrow_forwardInsoluble AgCl(s) precipitates when solutions of AgNO3(aq) and NaCl(aq) are mixed. AgNO3(aq) + NaCl(aq) AgCl(s) + NaNO3(aq) rH = ? To measure the energy evolved in this reaction, 250. mL of 0.16 M AgNO3(aq) and 125 mL of 0.32 M NaCl(aq) are mixed in a coffee-cup calorimeter. The temperature of the mixture rises from 21.15 C to 22.90 C. Calculate the enthalpy change for the precipitation of AgCl(s), in kJ/mol. (Assume the density of the solution is 1.0 g/mL and its specific heat capacity is 4.2 J/g K.)arrow_forward4.72 The picture shown depicts the species present at the start of a combustion reaction between methane, CH4 and oxygen, O2 (a) What is the limiting reactant? (b) Draw the resulting state after this set of reactants has reacted as far as possible.arrow_forward
- 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?arrow_forwardEthanol, 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.arrow_forward4-55 For the reaction: (a) How many moles of N2 are required to react completely with 1 mole of O2? (b) How many moles of N2O3 are produced from the complete reaction of 1 mole of O2? (c) How many moles of O2 are required to produce 8 moles of N2O3?arrow_forward
- list at least three quantities that must be conserved in chemical reactions.arrow_forward3.15 Ethanol, C2H5OH is found in gasoline blends used in many parts of North America. Write a balanced chemi- cal equation for the combustion of C2H5OH to form CO2 and HA.arrow_forwardFor this reaction, fill in the table with the indicated quantities for the balanced equation. 4 NH3(g) + 5 O2(g) → 4 NO(g) + 6 H2O(g)arrow_forward
- Acetone, (CH3)2CO, is an important industrial compound. Although its toxicity is relatively low, workers using it must be careful to avoid flames and sparks because this compound burns readily in air. Write the balanced equation for the combustion of acetone.arrow_forwardA 0.20 mol sample of magnesium burns in air to form 0.20 mol of solid MgO. What amount (moles) of oxygen (O2) is required for a complete reaction?arrow_forward4-77 To convert 1 mol of iron(III) oxide to its elements requires 196.5 kcal: How many grams of iron can be produced if 156.0 kcal of heat is absorbed by a large-enough sample of iron(III) oxide?arrow_forward
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