Chapter 9

HEINS09-095-117v4.qxd 12/30/06 1:58 PM Page 98
- Chapter 9 -
4. (a)
(b)
(c)
(d)
(e)
(0.00844 mol NiSO 4 )a 154.8 g b = 1.31 g NiSO
mol
4
(0.0600 mol HC 2 H 3 O 2 )a 60.05 g b = 3.60 g HC 2 H 3 O 2
mol
(0.725 mol Bi 2 S 3 )a 514.2 g b = 373 g Bi
mol
2 S 3
(4.50 * 10 21 1 mol
molecules C 6 H 12 O 6 )¢
6.022 * 10 23 molecules ≤ a 180.2 g b
mol
= 1.35g C 6 H 12 O 6
(75 mL solution2a 1.175 g
mL ba0.200 g K 2CrO 4
b = 18 g K
g solution
2 CrO 4
5. Larger number of molecules: 10.0 g H 2 O or 10.0 g H 2 O 2
Water has a lower molar mass than hydrogen peroxide. 10.0 grams of water has a lower
molar mass, contains more moles, and therefore more molecules than 10.0 g of H 2 O 2 .
6. Larger number of molecules: 25.0 g HCl or 85 g C 6 H 12 O 6
125.0 g HCl2a 1 mol
36.46 g ba6.022 * 1023 molecules
b = 4.13 * 10 23 molecules HCl
mol
185.0 g C 6 H 12 O 6 2a 1 mol
180.2 g ba6.022 * 1023 molecules
b
mol
HCl contains more molecules
= 2.84 * 10 23 molecules C 6 H 12 O 6
7. Mole ratios
2 C 3 H 7 OH + 9 O 2 ¡ 6 CO 2 + 8 H 2 O
(a)
(b)
(c)
6 mol CO 2
8 mol H 2 O
(d)
2 mol C 3 H 7 OH
2 mol C 3 H 7 OH
2 mol C 3 H 7 OH
6 mol CO 2
(e)
9 mol O 2 8 mol H 2 O
9 mol O 2
8 mol H 2 O
(f)
6 mol CO 2 9 mol O 2
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