Answers to Chapter 3

(please contact me if you think there is an error)

30
a 0.897 mol N2O4
b 1.43 mol N atoms
c  0.94 mol N (error in solutions manual; there are 3 moles N for each mole C7H5(NO2)3

32
3 x 1022 Fe atoms

36
a 69 atoms
b 5C per 11H or .454 C atom/ H atom
c 0.566 g Ge/ g S
d 128.3 g S
e 8.210 x 1023 C atoms

38
74.046% C
8.6349% N
7.4566% H
9.8634% O    all by mass

48
C40H56

52
I found it easiest to find the empirical formula, then the molecular formula and finally the mass %.
The molecule is C7H8O (both emp. and molecular formulae)
78% C, 7.4%H and by by subtraction 14.6% O.
(minor correction from solutions manual)

56 CH4, methane, has 4 H's per C and will thus produce 2 moles H2O per mole methane.
This is the highest.

58
a +4
b +2
c +7
d +6
e +2.5 (not an integer!) for S4O6 2-

66 Notice that each of these is electrically NEUTRAL
a Mg(ClO4)2
b Pb(C2H3O2)2
c SnO2
d HI
e HClO2
f NaHSO3
g Ca(H2PO4)2
h AlPO4
i N2O4
jS2Cl2
Some of these are exotic!! There is a list of ions to learn on the Web.

90 ZnSO4. 7H2O (there are 7 waters)