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(A) an ionic solid
(B) a molecular solid
(C) a covalent network solid
(D) a polymer
2. What would be the concentration of
aluminum ion, [Al³⁺], when Al(NO3)3(s) is
added to distilled water to produce a solution
in which the concentration of nitrate, [NO3⁻],
is 1.00 M?
(A) 0.100 M
(B) 0.330 M
(C) 1.00 M
(D) 3.00 M
3. To determine the percentage of water in a
hydrated salt, a student heated a 1.2346 g
sample of the salt for 30 minutes; when
cooled to room temperature, the sample
weighed 1.1857g. After the sample was
heated for an additional 10 minutes and
again cooled to room temperature. The final
mass of the sample was 1.1632 g. Which of
the following should the student do next?
(A) Calculate the percentage of water in the
hydrated salt using the smallest mass value.
(B) Repeat the experiment with a new sample
and average the results.
(C) Reheat the sample until its mass stays
constant.
(D) Calculate the percentage of water in the
hydrated salt by calculating the average of
the mass values acquired after the two
heatings.
4. In which case is the oxygen not acting as an
oxidizing agent?
(A) 2 C(s) + O₂(g) → 2 CO(g)
(B) S(s) + O₂(g) → SO₂(g)
(C) 2 F₂(g) + O₂(g) → 2 OF₂(g)
(D) 2 Na(s) + O₂(g) → Na₂O₂(s)
5. When 0.040 mol of Al reacts with 0.040 mol of
O₂, how many moles of Al₂O₃ can be formed?
(A) 0.010 mol
(B) 0.020 mol
(C) 0.033 mol
(D) 0.040 mol
6. Under which condition can an endothermic
reaction be thermodynamically favorable?
(A) ΔS is negative
(B) TΔS > ΔH
(C) TΔS = 0
(D) There are no conditions