120 CHAPTER 3: Chemical Equations and Reaction Stoichiometry
is prepared by diluting 4.50 mL of this concentrated
HCl solution to 100.00 mL with water. Then 10.0 mL of
this dilute HCl solution reacts with an AgNO 3 solution
according to the following reaction.HCl(aq)AgNO 3 (aq)88nHNO 3 (aq)AgCl(s)How many milliliters of 0.108 M AgNO 3 solution is
required to precipitate all of the chloride as AgCl(s)?
104.In a particular experiment, 272 g of phosphorus, P 4 ,
reacted with excess oxygen to form tetraphosphorus
decoxide, P 4 O 10 , in 89.5% yield. In the second step
reaction, a 97.8% yield of H 3 PO 4 was obtained.
(a) Write the balanced equations for these two reaction
steps.
(b) What mass of H 3 PO 4 was obtained?
105.Magnesium displaces copper from a dilute solution of cop-
per(II) sulfate; the pure copper will settle out of the solu-
tion.Mg(s)CuSO 4 (aq)88nMgSO 4 (aq)Cu(s)A copper(II) sulfate solution is mixed by dissolving 25.000 g
of copper(II) sulfate, and then it is treated with an excessof magnesium metal. The mass of copper collected is 8.786
g after drying. Calculate the percent yield of copper.
106.Suppose you are designing an experiment for the prepa-
ration of hydrogen. For the production of equal amounts
of hydrogen, which metal, Zn or Al, is less expensive if Zn
costs about half as much as Al on a mass basis?Zn2HCl88nZnCl 2 H 2
2Al6HCl88n2AlCl 3 3H 2107.Gaseous chlorine and gaseous fluorine undergo a com-
bination reaction to form the interhalogen compound
ClF.
(a) Write the chemical equation for this reaction.
(b) Calculate the mass of fluorine needed to react with
3.47 g of Cl 2.
(c) How many grams of ClF are formed?
108.It has been estimated that 93% of all atoms in the entire
universe are hydrogen and that the vast majority of those
remaining are helium. Based on only these two elements
and the above-mentioned values, estimate the mass per-
centage composition of the universe.