Sample Problems that are relatively easy and cover chapters 1 through 6 material
Many of these problems are easy but a good warm up.
CHM 2045 exam problems are often 2 or 3 step problems. Students seems to find these
difficult because they have not done enough problems to comfortable in solving our
questions in 4 to5 minutes. CHM 2045 students should be able to do any of these
problems in 4 minutes or less
1. A 52.5 lb bag of topsoil will cover 12 square feet to a depth of 1.5 inches. How many
pounds of topsoil will be required to cover a plot 205 m by 315 m to a depth of 6.5 cm?
1) 5.19 x 10
6
lbs
2)
5.19 x 10
8
lbs
3) 9.88 x 10
4
lbs
4) 9.88 x 10
8
lbs
5) 7.98 x 10
5
lbs
2. Which of the following name formula pairs are NOT CORRECT?
A) Lead (II) sulfate, PbSO
4
F) Calcium oxide, CaO
K) Aluminum iodide, AlI
3
B) Phosphine, PH
3
G) Aluminum sulfite, Al
2
(SO
3
)
2
L) Calcium floride, CaF
2
C) Nitric oxide, NO
H) Lead (II) sulfite, PbSO
3
M) Potassium permanganate,
KMnO
4
D) Manganese (IV) oxide, Mn
4
O
2
I) Cobalt (III) oxide, Co
2
O
3
N) Sodium chlorate Na
2
ClO
3
E) Ammonium acetate,
NH
4
CH
3
CO
2
J) Beryllium phosphate. Be
3
(PO
4
)
2
O) Ammonium carbonate,
(NH
4
)
2
CO
3
1) A, C, F
2) D, G, N
3) C, H, N
4) C, J, K
5) A, H, I
3. Magnesium has three isotopes:
24
Mg [23.985042 u],
25
Mg [24.985836 u] and
26
Mg
[25.982593 u].
Knowing that the atomic mass of Magnesium is 24.31 u and the percent
abundance of
24
Mg is 78.99%, calculate the percent abundance of
25
Mg.
1)
12.04 %
2)
11.51 %
3)
9.50 %
4)
6.25 %
5)
21.01 %
4. A package of aluminum foil contains 100 ft
2
and has a mass of 1 lb. Find the
thickness of aluminum foil in mm.
The density of Aluminum is 2.70g/cm
3
. Note: 1
lb= 45.36g.
1)
0.0018mm
2)
0.0046mm
3)
0.018mm
4)
0.0013mm
5)
0.46mm