26. Part B
101 . T, T, CE
Gases deviate from the ideal gas law when atoms and molecules are forced into close
proximity under high pressure and at low temperature because molecular volume and
intermolecular attractions become significant.102 . F, F
An increase in entropy means an increase in randomness; ordered crystals have low entropy.
103 . T, T, CE
Two electrons in the same orbital must have opposite spins because of the Pauli exclusion
principle, which states that two electrons within a given atom can never have the same four
quantum numbers.
104 . F, T
Atom A wants to fill its outer shell with 8 electrons, while B wants to lose its 2 valence
electrons. Therefore, B donates one electron to two molecules of A to form A 2 B.
105 . T, F
CO 2 is able to sublimate because its phase diagram has the region that allows solids to
sublimate and gases to deposit at atmospheric temperature and pressure. In the lab at high
pressures, liquid CO 2 can be formed.
106 . T, F
In order of decreasing entropy: gas > liquid > solid.
107 . T, T, CE
Bonds between different metal atoms in an alloy are much weaker than those between atoms
in pure metals. Therefore, breaking these bonds requires less energy than breaking the bonds
in pure metals. Since melting and freezing points are lowered as the stability of the bonds
decreases, they tend to be lower in alloys than in pure metals. Alternatively, you can think of
an alloy as a solid solution with impurities that decrease the melting point.
108 . F, T