Nonelectrolytes do not dissolve in water and do not conduct electricity. Strong electrolytes
dissociate completely in water. For example, NaCl will conduct electricity very well. Weak
electrolytes such as formic acid (HCHO 2 ) will dissociate slightly in water to H+ and CHO 2 – and
will conduct electricity. Statement II, however, is not the correct explanation for statement I.
In fact, it is the other way around: A solution of nonelectrolytes does not conduct electricity
because no ions are formed.110 . T, T
The kinetic molecular theory predicts that heavier gases will diffuse more slowly than lighter
ones. This was proven in 1832 by Thomas Graham. Because of this theory, SO 3 (MW 80) would
diffuse more slowly than CO 2 (MW 44). SO 3 has a trigonal planar structure, with a bond angle of
120°. CO 2 is linear, and thus has a bond angle of 180°. This, however, has nothing to do with the
rate of diffusion.
111 . F, F
Hydrogen bonding is strongest between hydrogen and highly electronegative atoms such as F,
Cl, N, O. There is no H bonding between hydrogen and noble gases.
112 . T, F
An electron in the 3s subshell may occasionally enter an excited state and jump into the 3p
subshell. The Heinsenberg uncertainty principle states that it is impossible to simultaneously
determine with perfect accuracy both the momentum and position of a particle.
113 . F, F
∆G, the Gibbs free energy, is the energy of a system available to do work. The change in Gibbs
free energy can be determined by the equation ∆G = ∆H – T∆S. A negative ∆G indicates a
spontaneous reaction, while a positive ∆G indicates a nonspontaneous reaction. Entropy
never decreases in an isolated system.
114 . T, F
P 1 V 1 = P 2 V 2 . An increase in pressure leads to a decrease in volume because they are inversely
proportional.
115 . T, F
An amphoteric compound can act as either an acid or a base because it can react with either
H+ or OH–, depending on the nature of the reactants.