Unit+8+-+Stoichiometry

1) In the combustion analysis of 0.1127 g of glucose (C6H12O6), what mass, in grams, of CO2 would be produced? A. 0.0451 g B. 0.0825 g __C. 0.1652 g__ D. 0.4132 g E. 1.466 g 2) Sulfur dioxide reacts with chlorine to produce thionyl chloride (used as a drying agent for inorganic halides) and dichlorine oxide (used as a bleach for wood, pulp and textiles).

SO2(g) + 2Cl2(g) → SOCl2(g) + Cl2O(g)

If 0.400 mol of Cl2 reacts with excess SO2, how many moles of Cl2O are formed? A. 0.800 mol B. 0.400 mol __C. 0.200 mol__ D. 0.100 mol E. 0.0500 mol

3) Aluminum oxide (used as an adsorbent or a catalyst for organic reactions) forms when aluminum reacts with oxygen.

4Al(s) + 3O2(g) → 2Al2O3(s)

A mixture of 82.49 g of aluminum ( = 26.98 g/mol) and 117.65 g of oxygen ( = 32.00 g/mol) is allowed to react. What mass of aluminum oxide ( = 101.96 g/mol) can be formed? A. 155.8 g B. 200.2 g C. 249.9 g D. 311.7 g

E. 374.9 g 4) Magnesium (used in the manufacture of light alloys) reacts with iron(III) chloride to form magnesium chloride and iron.

3Mg(s) + 2FeCl3(s) → 3MgCl2(s) + 2Fe(s)

A mixture of 41.0 g of magnesium ( = 24.31 g/mol) and 175 g of iron(III) chloride ( = 162.2 g/mol) is allowed to react. Identify the limiting reactant and determine the mass of the excess reactant present in the vessel when the reaction is complete. A. Limiting reactant is Mg; 67 g of FeCl3 remain. B. Limiting reactant is Mg; 134 g of FeCl3 remain. C. Limiting reactant is Mg; 104 g of FeCl3 remain. __D. Limiting reactant is FeCl3; 3 g of Mg remain.__

E. Limiting reactant is FeCl3; 87 g of Mg remain. 5) Tetraphosphorus hexaoxide ( = 219.9 g/mol) is formed by the reaction of phosphorus with oxygen gas.

P4(s) + 3O2(g) → P4O6(s)

If a mixture of 75.3 g of phosphorus and 38.7 g of oxygen produce 43.3 g of P4O6, what is the percent yield for the reaction? A. 57.5% __B. 48.8%__ C. 38.0% D. 32.4% E. 16.3% 6) Methanol (CH4O) is converted to bromomethane (CH3Br) as follows:

CH4O + HBr → CH3Br + H2O

If 12.23 g of bromomethane are produced when 5.00 g of methanol is reacted with excess HBr, what is the percentage yield? A. 40.9% __B. 82.6%__ C. 100.% D. 121% E. 245% 7) A 0.150 M sodium chloride solution is referred to as a physiological saline solution because it has the same concentration of salts as normal human blood. Calculate the mass of solute needed to prepare 275.0 mL of a physiological saline solution. A. 41.3 g B. 31.9 g C. 16.1 g D. 8.77 g __E. 2.41 g__ 8) Copper(II) sulfide, CuS, is used in the development of aniline black dye in textile printing. What is the maximum mass of CuS which can be formed when 38.0 mL of 0.500 M CuCl2 are mixed with 42.0 mL of 0.600 M (NH4)2S? Aqueous ammonium chloride is the other product. A. 2.41 g B. 1.82 g C. 1.21 g D. 0.909 g E. 0.044 g 9) Aluminum will react with bromine to form aluminum bromide (used as an acid catalyst in organic synthesis).

Al(s) + Br2(l) → Al2Br6(s) [unbalanced]

How many moles of Al are needed to form 2.43 mol of Al2Br6? A. 7.29 mol B. 4.86 mol C. 2.43 mol D. 1.62 mol E. 1.22 mol 10) How many grams of sodium fluoride (used in water fluoridation and manufacture of insecticides) are needed to form 485 g of sulfur tetrafluoride?

3SCl2(l) + 4NaF(s) → SF4(g) + S2Cl2(l) + 4NaCl(s) A. 1940 g B. 1510 g C. 754 g D. 205 g E. 51.3 g 11) Magnesium reacts with iron(III) chloride to form magnesium chloride (which can be used in fireproofing wood and in disinfectants) and iron.

3Mg(s) + 2FeCl3(s) → 3MgCl2(s) + 2Fe(s)

A mixture of 41.0 g of magnesium ( = 24.31 g/mol) and 175 g of iron(III) chloride ( = 162.2 g/mol) is allowed to react. What mass of magnesium chloride = 95.21 g/mol) is formed? A. 68.5 g MgCl2 B. 77.0 g MgCl2 C. 71.4 g MgCl2 D. 107 g MgCl2 E. 154 g MgCl2 12) Potassium chloride is used as a substitute for sodium chloride for individuals with high blood pressure. Identify the limiting reactant and determine the mass of the excess reactant remaining when 7.00 g of chlorine gas reacts with 5.00 g of potassium to form potassium chloride. A. Potassium is the limiting reactant; 2.47 g of chlorine remain. B. Potassium is the limiting reactant; 7.23 g of chlorine remain. C. Chlorine is the limiting reactant; 4.64 g of potassium remain.

D. Chlorine is the limiting reactant; 2.70 g of potassium remain. E. No limiting reagent: the reactants are present in the correct stoichiometric ratio. 13) Hydrochloric acid is widely used as a laboratory reagent, in refining ore for the production of tin and tantalum, and as a catalyst in organic reactions. Calculate the number of moles of HCl in 62.85 mL of 0.453 M hydrochloric acid. A. 28.5 mol B. 1.04 mol C. 0.139 mol __D. 0.0285 mol__ E. 0.00721 mol