Pre-Midterm Practice Questions
CHMI 1006 EL 01 2025F:
These practice questions are provided here and full solutions are given during a tutorial style
lecture. They are a selection of some questions that I have asked on previous year midterm or
final exams. They are listed here as an opportunity for you to get extra practice on problem
solving. Please note that these are only a selection of questions from previous exams. They do
not represent a previous exam in full.
1. This question was from a previous year midterm exam:
Gallium has an atomic mass of 69.723u. The abundance of Ga-69 (68.926u) is 60.11%.
What is the atomic mass, in u, of the other isotope?
2. This question was from a previous year midterm exam:
a) Provide the name for Ba(NO3)2
b) Provide the chemical formula for disulfur tetrafluoride
c) Provide the structure for 3,3-dimethylpent-1-yne
d) Provide the name
for
3. This question was from a previous year midterm exam:
Consider the following combustion reaction: πΆπ₯ π»π¦ ππ§ + π2 → πΆπ2 + π»2 π. Combustion
analysis of 1.200 g of the oxygen containing hydrocarbon produced 2.086 g of CO2 and
1.134 g of H2O. Determine the empirical formula.
4. This question was from a previous year final exam:
Balance the equation ππ32− (ππ) + πππ4− (ππ) → ππ42− (ππ) + ππ2+ in acidic media.
5. This question was from a previous year midterm exam:
Lead ions can be precipitated from solution with KCl according to the following balanced
equation:
ππ 2+ (ππ) + 2πΎπΆπ(ππ) → πππΆπ2 (π ) + 2πΎ + (ππ)
When 28.5 g KCl is added to a solution containing 25.7 g Pb2+, a PbCl2 precipitate forms.
The precipitate is filtered and dried and found to have a mass of 29.4g. Determine the
theoretical yield and percent yield for this reaction.
6. This question was from a previous year final exam.
A gas occupies 3.33 L at 2.23 bar. What is the volume at 2.50 bar if the temperature and
number of moles remain constant?
7. This question was from a previous year final exam.
A total of 0.35g of Ar(g) are contained in a 300 mL vessel at a pressure of 1.3 bar. Calculate
the temperature of the gas. Recall that 100 kPa = 1 bar and 1000mL = 1L and J = L kPa
0
