Answers to Chapter 4

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listed below!

26
a (NH4)2Cr2O7 = Cr2O3 + N2 + 4 H2O
b 3NO2 + H2O = 2HNO3 + NO
c 2H2S + SO2 = 3S + 2H2O
d SO2Cl2 + 8HI = H2S + 2H2O + 2HCl + 4I2

34
135 kg HNO3

38
1.22 g H2

50
We calculate 2.3 M ethanol which is greater than 1.71 M given in ex. 4-8.

54
Add 88.2 mL 0.496M KCl to 250 mL volumetric flask, add distilled water to the mark.
 (stop several times to mix)

64
[HCl]= 0.1215 M
CaCO3 consumes 1.998 mmole HCl 
Ba(OH)2 consumers 1.039 mmol HCl

68
zinc sulfate is the limiting reagent so 0.0866 moles of each product are synthesized.
28.7 g of mixture results.

74
5.0x102 g C2H2Cl2

86.
Seawater is 0.49 M NaCl
9.1x105 L need to be evaporated.

90.  This is hard.
There are two separate reactions where Mg and Al each produce hydrogen.
The alloy is 24% Mg by mass.

If you are stumped, you may be able to work backwards from the answer.