Q. In the reaction 2Cr2O7^2- + 14H+ + 6e^- → 4Cr^3+ + 7H2O, what is the role of Cr2O7^2-?
A.Oxidizing agent
B.Reducing agent
C.Neutral agent
D.None of the above
Solution
Cr2O7^2- is reduced to Cr^3+, making it the oxidizing agent.
Correct Answer: A — Oxidizing agent
Q. In the reaction 2Fe + 3Cl2 → 2FeCl3, how many moles of Cl2 are needed to react with 4 moles of Fe?
A.3 moles
B.6 moles
C.4 moles
D.2 moles
Solution
According to the stoichiometry, 2 moles of Fe require 3 moles of Cl2. Therefore, 4 moles of Fe will require 6 moles of Cl2.
Correct Answer: B — 6 moles
Q. In the reaction 2Fe2O3 + 3C → 4Fe + 3CO2, what is being oxidized?
A.Fe2O3
B.C
C.Fe
D.CO2
Solution
Carbon (C) is being oxidized to carbon dioxide (CO2).
Correct Answer: B — C
Q. In the reaction 2Fe^3+ + 2I^- → 2Fe^2+ + I2, which species is the reducing agent?
A.Fe^3+
B.I^-
C.Fe^2+
D.I2
Solution
I^- donates electrons to Fe^3+, thus it is the reducing agent.
Correct Answer: B — I^-
Q. In the reaction 2H2 + O2 → 2H2O, how many grams of oxygen are required to react with 4 grams of hydrogen?
A.16 g
B.8 g
C.4 g
D.2 g
Solution
First, calculate moles of H2: 4 g / 2 g/mol = 2 moles. From the reaction, 2 moles of H2 require 1 mole of O2. Therefore, 2 moles of O2 = 32 g.
Correct Answer: B — 8 g
Q. In the reaction 2H2 + O2 → 2H2O, how many grams of water are produced from 4 grams of hydrogen?
A.18 g
B.36 g
C.54 g
D.72 g
Solution
4 grams of H2 is 2 moles (4 g / 2 g/mol). According to the equation, 2 moles of H2 produce 2 moles of H2O, which is 36 g (2 moles x 18 g/mol).
Correct Answer: B — 36 g
Q. In the reaction 2H2 + O2 → 2H2O, how many moles of O2 are required to completely react with 6 moles of H2?
A.2 moles
B.3 moles
C.4 moles
D.6 moles
Solution
From the balanced equation, 2 moles of H2 require 1 mole of O2. Therefore, 6 moles of H2 will require (6/2) = 3 moles of O2.
Correct Answer: B — 3 moles
Q. In the reaction 2H2 + O2 → 2H2O, how many moles of O2 are required to react with 6 moles of H2?
A.3 moles
B.4 moles
C.6 moles
D.2 moles
Solution
According to the stoichiometry of the reaction, 2 moles of H2 require 1 mole of O2. Therefore, 6 moles of H2 will require (6/2) = 3 moles of O2.
Correct Answer: A — 3 moles
Q. In the reaction 2H2 + O2 → 2H2O, how many moles of water are produced from 4 moles of hydrogen?
A.2 moles
B.4 moles
C.6 moles
D.8 moles
Solution
According to the stoichiometry of the reaction, 2 moles of H2 produce 2 moles of H2O. Therefore, 4 moles of H2 will produce 4 moles of H2O.
Correct Answer: B — 4 moles
Q. In the reaction 2H2 + O2 → 2H2O, what is the ratio of moles of hydrogen to moles of oxygen?
A.1:1
B.2:1
C.2:2
D.1:2
Solution
The balanced equation shows that 2 moles of H2 react with 1 mole of O2, giving a ratio of 2:1.
Correct Answer: B — 2:1
Q. In the reaction 2H2 + O2 → 2H2O, which element is oxidized?
A.H
B.O
C.H2O
D.None
Solution
Oxygen (O) is oxidized as it goes from 0 in O2 to -2 in H2O.
Correct Answer: B — O
Q. In the reaction 2SO2(g) + O2(g) ⇌ 2SO3(g), what happens to the equilibrium if the volume of the container is decreased?
A.Shift to the right
B.Shift to the left
C.No change
D.Increase the rate of reaction
Solution
Decreasing the volume increases the pressure, and the equilibrium will shift towards the side with fewer moles of gas, which is the right side (2 moles of SO3).
Correct Answer: A — Shift to the right
Q. In the reaction 2SO2(g) + O2(g) ⇌ 2SO3(g), what is the effect of increasing the pressure on the equilibrium?
A.Shift to the left
B.Shift to the right
C.No effect
D.Depends on the temperature
Solution
Increasing the pressure will shift the equilibrium towards the side with fewer moles of gas, which is the right side in this case (2 moles of SO3).
Correct Answer: B — Shift to the right
Q. In the reaction 2SO2(g) + O2(g) ⇌ 2SO3(g), what will happen if SO3 is removed from the system?
A.Equilibrium shifts to the left
B.Equilibrium shifts to the right
C.No change
D.Equilibrium constant increases
Solution
Removing SO3 will shift the equilibrium to the right to produce more SO3, according to Le Chatelier's principle.
Correct Answer: B — Equilibrium shifts to the right
Q. In the reaction 3H2 + N2 → 2NH3, how many moles of nitrogen are required to produce 6 moles of ammonia?
A.3 moles
B.2 moles
C.1 mole
D.4 moles
Solution
According to the stoichiometry, 2 moles of NH3 require 1 mole of N2. Therefore, 6 moles of NH3 will require 3 moles of N2.
Correct Answer: A — 3 moles
Q. In the reaction 3H2 + N2 → 2NH3, which element is oxidized?
A.H
B.N
C.NH3
D.None
Solution
Hydrogen (H) is oxidized as it goes from an oxidation state of 0 to +1 in NH3.
Correct Answer: A — H
Q. In the reaction 4Fe + 3O2 → 2Fe2O3, how many moles of Fe are required to react with 6 moles of O2?
A.4 moles
B.6 moles
C.8 moles
D.12 moles
Solution
From the balanced equation, 3 moles of O2 react with 4 moles of Fe. Therefore, 6 moles of O2 will require (4/3) * 6 = 8 moles of Fe.
Correct Answer: C — 8 moles
Q. In the reaction 4Fe + 3O2 → 2Fe2O3, how many moles of Fe2O3 are produced from 12 moles of Fe?
A.2 moles
B.3 moles
C.4 moles
D.6 moles
Solution
From the balanced equation, 4 moles of Fe produce 2 moles of Fe2O3. Therefore, 12 moles of Fe will produce (12/4) x 2 = 6 moles of Fe2O3.
Correct Answer: C — 4 moles
Q. In the reaction 4Fe + 3O2 → 2Fe2O3, how many moles of Fe2O3 can be produced from 12 moles of Fe?
A.3 moles
B.6 moles
C.9 moles
D.12 moles
Solution
From the stoichiometry, 4 moles of Fe produce 2 moles of Fe2O3. Therefore, 12 moles of Fe will produce (12/4) x 2 = 6 moles of Fe2O3.
Correct Answer: B — 6 moles
Q. In the reaction 4Fe + 3O2 → 2Fe2O3, what is the oxidation state of iron in Fe2O3?
A.+2
B.+3
C.0
D.+1
Solution
In Fe2O3, iron has an oxidation state of +3.
Correct Answer: B — +3
Q. In the reaction CO(g) + 2H2(g) ⇌ CH3OH(g), what will happen if H2 is removed from the system at equilibrium?
A.Equilibrium shifts to the right
B.Equilibrium shifts to the left
C.No change
D.Equilibrium constant increases
Solution
Removing H2 will shift the equilibrium to the left to produce more H2, thus favoring the reactants.
Correct Answer: B — Equilibrium shifts to the left
Q. In the reaction CO(g) + 2H2(g) ⇌ CH3OH(g), what will happen if H2 is removed from the system?
A.Shift to the left
B.Shift to the right
C.No change
D.Increase the rate of reaction
Solution
Removing H2 will shift the equilibrium to the left to produce more H2, according to Le Chatelier's principle.
Correct Answer: A — Shift to the left
Q. In the reaction: 2A(g) ⇌ B(g) + C(g), if the volume of the container is decreased, what will happen to the equilibrium?
A.Shift to the left
B.Shift to the right
C.No change
D.Depends on temperature
Solution
Decreasing the volume increases the pressure, and the equilibrium will shift to the side with fewer moles of gas, which is the left side in this case.
Correct Answer: A — Shift to the left
Q. In the reaction: 2A(g) ⇌ B(g) + C(g), if the volume of the container is decreased, what will happen?
A.Shift to the left
B.Shift to the right
C.No change
D.Depends on the temperature
Solution
Decreasing the volume increases the pressure, and the equilibrium will shift towards the side with fewer moles of gas, which is the left side in this case.
Correct Answer: A — Shift to the left
Q. In the reaction: 2SO2(g) + O2(g) ⇌ 2SO3(g), what happens if the temperature is increased?
A.Shift to the right
B.Shift to the left
C.No change
D.Increase in Kp
Solution
If the reaction is exothermic, increasing the temperature will shift the equilibrium to the left, favoring the reactants.
Correct Answer: B — Shift to the left
Q. In the redox reaction 2Fe2O3 + 3C → 4Fe + 3CO2, what is the oxidation state of carbon in CO2?
A.0
B.+2
C.+4
D.-4
Solution
In CO2, the oxidation state of carbon is +4.
Correct Answer: C — +4
Q. In which of the following compounds does the central atom have sp3d hybridization?
A.PCl5
B.SiCl4
C.XeF4
D.NH4Cl
Solution
In PCl5, the phosphorus atom is sp3d hybridized, allowing it to form five P-Cl bonds.
Correct Answer: A — PCl5
Q. In which of the following compounds does the inductive effect play a significant role?
A.Benzene
B.Acetic acid
C.Cyclohexane
D.Ethylene
Solution
In acetic acid, the inductive effect of the –COOH group influences the acidity of the compound.
Correct Answer: B — Acetic acid
Q. In which of the following compounds is the bond order equal to 1?
A.N2
B.O2
C.H2
D.Cl2
Solution
H2 has a bond order of 1, indicating a single bond between the two hydrogen atoms.
Correct Answer: C — H2
Q. In which of the following conditions does a gas deviate most from ideal behavior?
A.High temperature and low pressure
B.Low temperature and high pressure
C.High temperature and high pressure
D.Low temperature and low pressure
Solution
A gas deviates most from ideal behavior at low temperatures and high pressures due to increased intermolecular forces.
Correct Answer: B — Low temperature and high pressure
