SAMPLE CHEMISTRY PLACEMENT EXAM QUESTIONS
WITH COMPLETE SOLUTIONS 100% 2023/2024
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: 2.00
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: 8.3 x 10⁸
The "calculator answer" is 8.2695.... x 10⁸. When the numbers in the numerator are subtracted the
result, 8.53, must be rounded to one decimal place, or 8.5. Since this number has two significant
figures, the result when it is divided by a number with 5 significant figures is limited to two significant
figures.
To the correct number of significant figures, the result of the following calculation
[(11.13 - 2.6) x 10⁴]/[103.15 x 10− ⁶]
should be reported as
Answer: 14
How many total atoms are in the formula
Al₂(CO₃)₃?
Answer: 36
How many electrons are in Br-?
, 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
What volume of 12.0 M HCl is required to
make 75.0 mL of 3.50 M HCl?
A) 0.560 mL B) 257 mL
C) 560. mL D) 21.9 mL
D) 1.12 × 10²
(2.80x10-³) (1.28 x 10¹)/(3.20 x 10-⁴)=
A) 1.27 × 10¹ B) 2.0 × 10²
C) 1.2 × 10⁶ D) 1.12 × 10²
Answer: D) AsH₃
Of the molecules below, only __________ is
polar.
A) CH₄ B) SbF₅
C) CO₂ D) AsH₃
B) Ge
WITH COMPLETE SOLUTIONS 100% 2023/2024
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: 2.00
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: 8.3 x 10⁸
The "calculator answer" is 8.2695.... x 10⁸. When the numbers in the numerator are subtracted the
result, 8.53, must be rounded to one decimal place, or 8.5. Since this number has two significant
figures, the result when it is divided by a number with 5 significant figures is limited to two significant
figures.
To the correct number of significant figures, the result of the following calculation
[(11.13 - 2.6) x 10⁴]/[103.15 x 10− ⁶]
should be reported as
Answer: 14
How many total atoms are in the formula
Al₂(CO₃)₃?
Answer: 36
How many electrons are in Br-?
, 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
What volume of 12.0 M HCl is required to
make 75.0 mL of 3.50 M HCl?
A) 0.560 mL B) 257 mL
C) 560. mL D) 21.9 mL
D) 1.12 × 10²
(2.80x10-³) (1.28 x 10¹)/(3.20 x 10-⁴)=
A) 1.27 × 10¹ B) 2.0 × 10²
C) 1.2 × 10⁶ D) 1.12 × 10²
Answer: D) AsH₃
Of the molecules below, only __________ is
polar.
A) CH₄ B) SbF₅
C) CO₂ D) AsH₃
B) Ge
