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HEINS09-095-117v4.qxd 12/30/06 1:58 PM Page 112<br />

- <strong>Chapter</strong> 9 -<br />

44. Composition of a mixture of and KCl.<br />

In the mixture only KCl reacts with AgNO 3 .<br />

KCl(aq) + AgNO 3 (aq) ¡ AgCl(s) + KNO 3 (aq)<br />

74.55 g KCl<br />

14.33 g AgCl2a b = 2.25 g KCl in the mixture<br />

143.7 g AgCl<br />

KNO 3<br />

- 112 -<br />

10.00 g mixture - 2.25 g KCl = 7.75 g KNO 3<br />

2.25 g KCl<br />

a b11002 = 22.5% KCl<br />

10.00 g mixture<br />

a 7.75 g KNO 3<br />

10.00 g mixture b11002 = 77.5% KNO 3<br />

45. The balanced equation is Zn + 2 HCl ¡ ZnCl 2 + H 2<br />

180.0 g Zn - 35 g Zn = 145 g Zn reacted with HCl<br />

(a)<br />

(b)<br />

(c)<br />

1145 g Zn2a 1 mol<br />

65.39 g ba1 mol H 2<br />

1 mol Zn b a 2.016 g b = 4.47 g H<br />

mol<br />

2 produced<br />

1145 g Zn2a 1 mol mol HCl<br />

ba2<br />

65.39 g 1 mol Zn ba36.46 g b = 162 g HCl reacted<br />

mol<br />

1180.0 g Zn2a 1 mol mol HCl<br />

ba2<br />

65.39 g 1 mol Zn ba36.46 g b = 201 g HCl reacts<br />

mol<br />

201 g - 162 g = 39 g more HCl needed to react wih the 180.0 g Zn<br />

46.<br />

Fe(s) + CuSO 4 (aq)<br />

2.0 mol 3.0 mol<br />

¡<br />

Cu(s)<br />

FeSO 4 (aq)<br />

(a) 2.0 mol Fe react with 2.0 mol CuSO 4 to yield 2.0 mol Cu and 2.0 mol FeSO 4 .<br />

1.0 mol CuSO 4 is unreacted. At the completion of the reaction, there will be<br />

2.0 mol Cu, 2.0 mol FeSO 4 , and 1.0 mol CuSO 4 .<br />

(b) Determine which reactant is limiting and then calculate the g FeSO 4 produced from<br />

that reactant.<br />

120.0 g Fe2a 1 mol mol Cu<br />

ba1<br />

55.85 g 1 mol Fe ba63.55 g b = 22.8 g Cu<br />

mol<br />

140.0 g CuSO 4 2a 1 mol 1 mol Cu<br />

ba ba 63.55 g b = 15.9 g Cu<br />

159.6 g 1 mol CuSO 4 mol<br />

Since CuSO 4 produces less Cu, it is the limiting reactant. Determine the mass of<br />

FeSO 4 produced from 40.0 g CuSO 4 .<br />

+

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