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Sample Chemistry Placement Exam
Questions with Certified Answers
Answer: Oxygen
Aluminum forms a +3 ion. In order for the formula unit Al₂X₃ to be electrically neutral, the element X must form a - 2 ion. Nonmetals in the oxygen column do this. Of these elements, only oxygen is a diatomic gas.
Aluminum reacts with element X to form a compound with the formula A₂X₃. Element X exists as diatomic molecules, X₂, in the gaseous state at normal temperature and pressure. Element
X must be?
Answer: 5
The balanced equation is 2 C₂H₄O + 5 O₂ → 4 CO₂ + 4 H₂O
What is the coefficient of O₂ when the following equation is balanced?
C₂H₄O + O₂ → CO₂ + H₂O
Answer: 2.
8.00 mol GeF₃H ( 1 mol GeH₄/ 4 mol GeF₃H) = 2.00 mol GeH₄
How many moles of GeH₄ are needed to form 8.00 moles of GeF₃H according to the following reaction?
GeH₄ + GeF₄ → 4 GeF₃H
Answer: A nonmetal
Nonmetals are toward the upper right of the periodic table. All the elements in the fluorine column are nonmetals.
According to its location in the periodic table, the element bromine (element # 35) is best described as
Answer: NaCl
HCl, hydrochloric acid, is a strong acid. NH₃, ammonia, is a weak base. In a solution of NaHCO₃, sodium hydrogen carbonate (baking soda), the hydrogen carbonate ion,
HCO₃- , acts as a base. Neither the sodium ion Na+, nor the chloride ion, Cl - , which form when NaCl is dissolved in water, has significant acidic or basic properties.
Which of the following species is neither acidic nor basic when dissolved in water
Answer: 2, 3, 6, 1
What are the coefficients for the following
reaction when it is properly balanced?
Na₃PO₄ + Ba(NO₃)₂ → NaNO₃ + Ba₃(PO₄)₂
A) 3.00 mol
Given that 4 NH₃ + 5 O₂→ 4 NO + 6 H₂O,
when 4.50 mol of H₂O are formed, the amount
of NO formed is
A) 3.00 mol B) 6.75 mol
C) 1.50 mol D) 4.50 mol
acid-base neutralization
What type of a reaction occurs when a sodium
hydroxide solution is mixed with an acetic
acid solution?
Answer: A) Ne
Which of the following atoms has the smallest
radius?
A) Ne B) O
C) Li D) B
Answer: Bent
What is the molecular geometry if you have a
double bond, a single bond and 1 lone pair
around the central atom?
D) 21.9 mL
B) Ge
Which one of the following is a metalloid?
A) S B) Ge C) C D) Pb
D) 18
A certain atom has a charge of -2 and has 16
protons and 16 neutrons in the nucleus.
How many electrons does this atom possess?
A) 34 B) 14 C) 32 D) 18
C) 0.
How many moles of pyridine (C₅H₅N) are
contained in 3.13 g of pyridine?
A) 0.00404 B) 25.
C) 0.0396 D) 0.
B) c + b/
Solve the following equation for x:
4x - b = 2x + c
A) c - b - 6
B) c + b/
C) c + b/
D) c - b/
d) 0.7881. m
Calculate the number of cubic meters of water in a fish tank holding 1.029 cubic yards of water. Hint, 1 meter = 1.093 yards.
a) 1.062 m³
b) 0.9414 m³
c) 1.125 m³
C₇H₁ 6(1) + 11 0₂(g) → 7 CO₂(g) + 8 H₂O(I)
0.584 mol
How many moles of CO2 will be produced when 8.34 grams of heptane, C₇H₁₆ are burned?
7,730 ml
What volume (in ml) would 0.345 moles of gaseous CO₂ occupy at STP? Hint, STP is at 0°C and 760 Torr where 22.4 liters contain one mole?
c) HNO₃
Which of the following is a strong acid?
a) NaCl b) NH₃
c) HNO₃ d)CaSO₄
c) CH₂O
Which of the following represent the empirical formula?
a) C₆H₁₂O₆ b) CH₂ = C(OH)₂
c) CH₂O
d) CH₃-C=O
H
a) N₂O₃
The formula for dinitrogen trioxide is
a) N₂O₃ b) NO₃
c) N₂O d) NO
d) 722 torr
Using the graph determine the pressure (in torr) when the temperature is 70 °C.
a) 698 torr b) 716 torr
c) 721 torr d) 722 torr
b) 4.2 x 10¹⁰ ng
Which of the following is the smallest mass?
a) 2.1 kg
b) 4.2 x 10¹⁰ ng
c) 5.8 x 10² g
d) 8.4 x 10⁴ cg
a) 0.15 M
If 250 mL of a 0.50 M NaCl solution is diluted to 840 mL, what is the molarity of the resulting solution?
a) 0.15 M
b) 6.7 M
c) 0.60 M
d) 1.7 M
c) Fe₂(SO₃)₃
Iron(III) sulfite has the formula
a) Fe₃SO₃
b) Fe₂(SO₄)₃
c) Fe₂(SO₃)₃
d) Fe₂SO₄
1.2 x 1024 atoms
How many atoms of carbon are in 24 grams of carbon?
d) 354 g
A solution is prepared by dissolving sugar in water. The solution is 25.0%, by mass, sugar. How many grams of WATER are in 472 grams of this solution?
a) 118 g
b) 157 g
c) 408 g
d) 354 g
c) 18.1 mL
26.0 g of a liquid that has a density of 1.44 g/mL needs to be measured out in a graduated cylinder. What volume should be used?
a) 37.4 mL
b) 0.0554 mL
c) 18.1 mL
d) 0.0267 mL
a) dinitrogen trioxide
Which of the following would be the correct name for N₂O₃?
a) dinitrogen trioxide
b) nitrogen(II) oxide
c) nitrogen(III) oxide
d) nitrogen oxide
d) 1.32 mol
How many moles of C₄F₈ are in 265 grams of C₄F₈?
a) 8.55 mol
b) 1.89 x 10-⁵ mol
c) 5.30 x 10⁴ mol
d) 1.32 mol
c) 29.89%
What is the percent, by mass, of oxygen in Zn(BrO₃)₂?
a) 24.83%
b) 39.00%
c) 29.89%
d) 39.79%
d) 37
Given: Z = 0.43Y + 12 ;
What is Y when Z = 28?
b) KS₂
c) K₂S₃
d) K₂S
b) 0.582 km
How many kilometers is 5.82 x 10⁴ cm?
a) 5.82 x 10³ km
b) 0.582 km
c) 5.82 x 10⁹ km
d) 5.82 km
a) 40
Data was collected on an experiment that relates "Stuff" to "Blips". Using a "best fit" line for the data, how much stuff would I have if I had 20 blips?
a) 40 b) 10 c) 20 d) 30
(d) Al(NO₃)₃
The correct formula for aluminum nitrate is
(a) Al₃N₂
(b) Al₃(NO₃)
(c) Al(NO₂)₃
(d) Al(NO₃)₃
(a) liquid to solid
A substance releases heat when it changes from
(a) liquid to solid
(b) solid to gas
(c) liquid to gas
(d) solid to liquid
(c) P
Which element has exactly five electrons in the highest principal energy level (the outer shell)?
