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31. The correct answer is (C). To dilute an acid, one slowly pours the acid into the water NOT vice versa.
32. The correct answer is (A). pH + pOH = 14 and pOH = –log[OH
–
].
33. The correct answer is (C). The group IV elements share in common the +2 and +4 oxidation states.
34. The correct answer is (C). Both CO and N
2
have triple bonds and the following electron dot structures:
:C:::O:
:N:::N:
35. The correct answer is (C). By definition, molarity is moles of substance/liter of solution. Since 1L
of H
2
O weighs 1000g, we need to determine how many moles of H
2
O constitute 1000g; this is 1000g/
18g/mole = 55.6 moles.
36. The correct answer is (B). A decay reaction that emits an electron or a positron is called a beta decay.
37. The correct answer is (E). Cesium has the lowest dissociation energy. The bond formed between
two cesium atoms is formed by sharing 6s electrons. This bond is formed by orbitals that are far from
the nucleus. A 6s bond is weaker than a bond formed by 1s, 2s, . . ., 5s electrons.
38. The correct answer is (D). Phosphorous can combine with the halogens to form PX
3
, PX
5
, or P
2
I
4
.
Nitrogen forms only NF
3
, N
2
F
2
, N
2
F
4
, and NCl
3
.
39. The correct answer is (A). The equation is multiplied by 2.5. 115g of C
2
H
5
OH are consumed, 135g
of H
2
O are produced, and 240g of O
2
are consumed.
40. The correct answer is (C). An oxidant becomes reduced because it removes electrons from the atom
being oxidized. Mn
+7
is reduced to Mn
+2
in this reaction.
41. The correct answer is (E).
12
44
= .27 and 
32
44
= .73