Problem 87
Why is the actual yield of a reaction almost always smaller than the theoretical yield?
Problem 88
Nitric oxide (NO) reacts with oxygen gas to form nitrogen dioxide \(\left(\mathrm{NO}_{2}\right)\), a dark-brown gas: $$ 2 \mathrm{NO}(g)+\mathrm{O}_{2}(g) \longrightarrow 2 \mathrm{NO}_{2}(g) $$ In one experiment, 0.886 mol of \(\mathrm{NO}\) is mixed with \(0.503 \mathrm{~mol}\) of \(\mathrm{O}_{2}\). Determine which of the two reactants is the limiting reactant. Calculate also the number of moles of \(\mathrm{NO}_{2}\) produced.
Problem 89
Consider the reaction $$ \mathrm{MnO}_{2}+4 \mathrm{HCl} \longrightarrow \mathrm{MnCl}_{2}+\mathrm{Cl}_{2}+2 \mathrm{H}_{2} \mathrm{O} $$ If \(0.86 \mathrm{~mol}\) of \(\mathrm{MnO}_{2}\) and \(48.2 \mathrm{~g}\) of \(\mathrm{HCl}\) react, which reactant will be used up first? How many grams of \(\mathrm{Cl}_{2}\) will be produced?
Problem 90
Nickel carbonyl can be prepared by the direct combination of nickel metal with carbon monoxide gas according to the following chemical equation: $$ \mathrm{Ni}(s)+4 \mathrm{CO}(g) \longrightarrow \mathrm{Ni}(\mathrm{CO})_{4}(s) $$ Determine the mass of nickel carbonyl that can be produced by the combination of \(50.03 \mathrm{~g} \mathrm{Ni}(s)\) with \(78.25 \mathrm{~g} \mathrm{CO}(g)\). Which reactant is consumed completely? How much of the other reactant remains when the reaction is complete?
Problem 91
Phosgene and ammonia gases can react to produce urea and ammonium chloride solids according to the following chemical equation: \(\mathrm{COCl}_{2}(g)+4 \mathrm{NH}_{3}(g) \longrightarrow \mathrm{CO}\left(\mathrm{NH}_{2}\right)_{2}(s)+2 \mathrm{NH}_{4} \mathrm{Cl}(s)\) Determine the mass of each product formed when \(52.68 \mathrm{~g}\) \(\mathrm{COCl}_{2}(g)\) and \(35.50 \mathrm{~g} \mathrm{NH}_{3}(g)\) are combined. Which reactant is consumed completely? How much of the other reactant remains when the reaction is complete?
Problem 92
Zinc metal reacts with aqueous silver nitrate to produce silver metal and aqueous zinc nitrate according to the following equation (unbalanced): $$ \mathrm{Zn}(s)+\mathrm{AgNO}_{3}(a q) \longrightarrow \mathrm{Ag}(s)+\mathrm{Zn}\left(\mathrm{NO}_{3}\right)_{2}(a q) $$ What mass of silver metal is produced when \(25.00 \mathrm{~g}\) Zn is added to a beaker containing \(105.5 \mathrm{~g} \mathrm{AgNO}_{3}\) dissolved in \(250 \mathrm{~mL}\) of water. Determine the mass amounts of each substance present in the beaker when the reaction is complete.
Problem 93
When combined, aqueous solutions of sulfuric acid and potassium hydroxide react to form water and aqueous potassium sulfate according to the following equation (unbalanced): $$ \mathrm{H}_{2} \mathrm{SO}_{4}(a q)+\mathrm{KOH}(a q) \longrightarrow \mathrm{H}_{2} \mathrm{O}(l)+\mathrm{K}_{2} \mathrm{SO}_{4}(a q) $$ Determine what mass of water is produced when a beaker containing \(100.0 \mathrm{~g} \mathrm{H}_{2} \mathrm{SO}_{4}\) dissolved in \(250 \mathrm{~mL}\) water is added to a larger beaker containing \(100.0 \mathrm{~g}\) KOH dissolved in \(225 \mathrm{~mL}\) water. Determine the mass amounts of each substance (other than water) present in the large beaker when the reaction is complete.
Problem 94
Hydrogen fluoride is used in the manufacture of Freons (which destroy ozone in the stratosphere) and in the production of aluminum metal. It is prepared by the reaction $$ \mathrm{CaF}_{2}+\mathrm{H}_{2} \mathrm{SO}_{4} \longrightarrow \mathrm{CaSO}_{4}+2 \mathrm{HF} $$ In one process, \(6.00 \mathrm{~kg}\) of \(\mathrm{CaF}_{2}\) is treated with an excess of \(\mathrm{H}_{2} \mathrm{SO}_{4}\) and yields \(2.86 \mathrm{~kg}\) of \(\mathrm{HF}\). Calculate the percent yield of HF.
Problem 95
Nitroglycerin \(\left(\mathrm{C}_{3} \mathrm{H}_{5} \mathrm{~N}_{3} \mathrm{O}_{9}\right)\) is a powerful explosive. Its decomposition may be represented by $$ 4 \mathrm{C}_{3} \mathrm{H}_{5} \mathrm{~N}_{3} \mathrm{O}_{9} \longrightarrow 6 \mathrm{~N}_{2}+12 \mathrm{CO}_{2}+10 \mathrm{H}_{2} \mathrm{O}+\mathrm{O}_{2} $$ This reaction generates a large amount of heat and gaseous products. It is the sudden formation of these gases, together with their rapid expansion, that produces the explosion. (a) What is the maximum amount of \(\mathrm{O}_{2}\) in grams that can be obtained from \(2.00 \times 10^{2} \mathrm{~g}\) of nitroglycerin? (b) Calculate the percent yield in this reaction if the amount of \(\mathrm{O}_{2}\) generated is found to be \(6.55 \mathrm{~g}\).
Problem 96
Titanium(IV) oxide \(\left(\mathrm{TiO}_{2}\right)\) is a white substance produced by the action of sulfuric acid on the mineral ilmenite \(\left(\mathrm{FeTiO}_{3}\right):\) $$ \mathrm{FeTiO}_{3}+\mathrm{H}_{2} \mathrm{SO}_{4} \longrightarrow \mathrm{TiO}_{2}+\mathrm{FeSO}_{4}+\mathrm{H}_{2} \mathrm{O} $$ Its opaque and nontoxic properties make it suitable as a pigment in plastics and paints. In one process, \(8.00 \times\) \(10^{3} \mathrm{~kg}\) of \(\mathrm{FeTiO}_{3}\) yielded \(3.67 \times 10^{3} \mathrm{~kg}\) of \(\mathrm{TiO}_{2}\). What is the percent yield of the reaction?
