Q. What is the product of the reaction between ammonia and an alkyl halide? (2023)
A.
Amine
B.
Alcohol
C.
Ether
D.
Aldehyde
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Solution
The product of the reaction between ammonia and an alkyl halide is an amine.
Correct Answer: A — Amine
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Q. What is the product of the reduction of Cr2O7²⁻ in acidic medium? (2019)
A.
CrO4²⁻
B.
Cr³⁺
C.
Cr²O3
D.
CrO2
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Solution
In acidic medium, Cr2O7²⁻ is reduced to Cr³⁺.
Correct Answer: B — Cr³⁺
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Q. What is the product of the reduction of permanganate ion (MnO4-) in acidic medium? (2019)
A.
MnO2
B.
Mn2O3
C.
Mn2+
D.
MnO4
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Solution
In acidic medium, the permanganate ion (MnO4-) is reduced to manganese ion (Mn2+).
Correct Answer: C — Mn2+
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Q. What is the relationship between the equilibrium constant (K) and the Gibbs free energy change (ΔG) at standard conditions? (2022)
A.
ΔG = -RT ln(K)
B.
ΔG = RT ln(K)
C.
ΔG = KRT
D.
ΔG = K/R
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Solution
The relationship is given by ΔG = -RT ln(K), where R is the gas constant and T is the temperature in Kelvin.
Correct Answer: A — ΔG = -RT ln(K)
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Q. What is the relationship between the rate of a reaction and the concentration of reactants according to the rate law? (2019)
A.
Directly proportional
B.
Inversely proportional
C.
Exponential
D.
No relationship
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Solution
The rate of a reaction is directly proportional to the concentration of reactants raised to their respective powers in the rate law.
Correct Answer: A — Directly proportional
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Q. What is the relationship between the vapor pressure of a solution and the mole fraction of the solvent? (2023)
A.
Directly proportional
B.
Inversely proportional
C.
No relationship
D.
Exponential relationship
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Solution
The vapor pressure of a solution is directly proportional to the mole fraction of the solvent.
Correct Answer: A — Directly proportional
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Q. What is the repeating unit of polystyrene? (2021)
A.
-CH2-CH2-
B.
-CH=CH2-
C.
-C6H5-
D.
-C3H6-
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Solution
The repeating unit of polystyrene is derived from the monomer styrene, which has the structure -CH=CH2-.
Correct Answer: B — -CH=CH2-
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Q. What is the role of an oxidizing agent in a redox reaction? (2020)
A.
It gains electrons
B.
It loses electrons
C.
It remains unchanged
D.
It increases the temperature
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Solution
An oxidizing agent gains electrons during a redox reaction, causing another species to be oxidized.
Correct Answer: A — It gains electrons
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Q. What is the role of dietary fiber in human health? (2021)
A.
Increase cholesterol
B.
Aid digestion
C.
Provide energy
D.
Enhance taste
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Solution
Dietary fiber aids digestion by promoting regular bowel movements and preventing constipation.
Correct Answer: B — Aid digestion
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Q. What is the role of enzymes in the human body? (2021)
A.
Store energy
B.
Speed up chemical reactions
C.
Transport oxygen
D.
Regulate temperature
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Solution
Enzymes act as catalysts that speed up chemical reactions in the body, facilitating various metabolic processes.
Correct Answer: B — Speed up chemical reactions
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Q. What is the role of MnO4⁻ in acidic medium during redox reactions? (2020)
A.
Oxidizing agent
B.
Reducing agent
C.
Neutral agent
D.
Catalyst
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Solution
MnO4⁻ acts as an oxidizing agent in acidic medium, as it gains electrons and is reduced.
Correct Answer: A — Oxidizing agent
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Q. What is the role of nitrogen oxides in the environment? (2021)
A.
Ozone formation
B.
Greenhouse effect
C.
Acid rain
D.
All of the above
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Solution
Nitrogen oxides contribute to ozone formation, the greenhouse effect, and are a precursor to acid rain.
Correct Answer: D — All of the above
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Q. What is the role of phytoplankton in the carbon cycle? (2020)
A.
Carbon storage
B.
Carbon release
C.
Carbon transformation
D.
Carbon transportation
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Solution
Phytoplankton absorb carbon dioxide during photosynthesis, playing a crucial role in carbon storage in the ocean.
Correct Answer: A — Carbon storage
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Q. What is the role of phytoplankton in the environment? (2019)
A.
Carbon dioxide production
B.
Oxygen production
C.
Soil erosion
D.
Water pollution
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Solution
Phytoplankton are crucial for oxygen production through photosynthesis and play a significant role in the carbon cycle.
Correct Answer: B — Oxygen production
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Q. What is the role of preservatives in food? (2020)
A.
Enhance flavor
B.
Increase shelf life
C.
Add color
D.
Improve texture
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Solution
Preservatives are added to food to prevent spoilage and increase shelf life by inhibiting the growth of microorganisms.
Correct Answer: B — Increase shelf life
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Q. What is the significance of the Langmuir isotherm in surface chemistry? (2023)
A.
It describes multilayer adsorption.
B.
It assumes a fixed number of adsorption sites.
C.
It is applicable only to physisorption.
D.
It does not consider temperature effects.
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Solution
The Langmuir isotherm assumes a fixed number of adsorption sites and describes monolayer adsorption on a surface.
Correct Answer: B — It assumes a fixed number of adsorption sites.
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Q. What is the standard enthalpy change (ΔH°) for the formation of water from its elements? (2022)
A.
-285.83 kJ/mol
B.
0 kJ/mol
C.
285.83 kJ/mol
D.
-241.82 kJ/mol
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Solution
The standard enthalpy change for the formation of water from its elements (H2 and O2) is -285.83 kJ/mol.
Correct Answer: A — -285.83 kJ/mol
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Q. What is the standard enthalpy change (ΔH°) for the reaction: C(s) + O2(g) → CO2(g)? (2022)
A.
It is always positive.
B.
It is always negative.
C.
It can be zero.
D.
It depends on the temperature.
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Solution
The standard enthalpy change for combustion reactions, such as the formation of CO2 from carbon and oxygen, is typically negative, indicating that the reaction is exothermic.
Correct Answer: B — It is always negative.
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Q. What is the standard reduction potential of a half-reaction? (2022)
A.
The tendency to gain electrons
B.
The tendency to lose electrons
C.
The energy released during oxidation
D.
The energy absorbed during reduction
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Solution
The standard reduction potential indicates the tendency of a species to gain electrons, thus being reduced.
Correct Answer: A — The tendency to gain electrons
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Q. What is the standard reduction potential of the half-reaction Cu2+ + 2e- → Cu? (2022)
A.
+0.34 V
B.
+0.76 V
C.
-0.34 V
D.
-0.76 V
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Solution
The standard reduction potential for the half-reaction Cu2+ + 2e- → Cu is +0.76 V, indicating a strong tendency to gain electrons.
Correct Answer: B — +0.76 V
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Q. What is the standard reduction potential of the half-reaction Fe^3+ + 3e- → Fe? (2022)
A.
+0.77 V
B.
+0.44 V
C.
-0.77 V
D.
-0.44 V
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Solution
The standard reduction potential for the half-reaction Fe^3+ + 3e- → Fe is +0.77 V, indicating a strong tendency to gain electrons.
Correct Answer: A — +0.77 V
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Q. What is the standard temperature and pressure (STP) in Kelvin and atm? (2020)
A.
0 K and 1 atm
B.
273 K and 1 atm
C.
100 K and 1 atm
D.
273 K and 0 atm
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Solution
Standard temperature and pressure (STP) is defined as 273 K and 1 atm.
Correct Answer: B — 273 K and 1 atm
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Q. What is the term for the change of state from solid directly to gas? (2020)
A.
Sublimation
B.
Deposition
C.
Evaporation
D.
Condensation
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Solution
Sublimation is the process where a solid changes directly into a gas without passing through the liquid state.
Correct Answer: A — Sublimation
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Q. What is the term for the change of state from solid to gas without passing through the liquid state? (2020)
A.
Sublimation
B.
Deposition
C.
Evaporation
D.
Condensation
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Solution
Sublimation is the process where a solid changes directly into a gas without becoming a liquid.
Correct Answer: A — Sublimation
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Q. What is the term for the maximum amount of adsorbate that can be adsorbed on a given mass of adsorbent? (2020)
A.
Adsorption capacity
B.
Saturation point
C.
Equilibrium concentration
D.
Adsorption isotherm
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Solution
The maximum amount of adsorbate that can be adsorbed on a given mass of adsorbent is referred to as the adsorption capacity.
Correct Answer: A — Adsorption capacity
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Q. What is the term for the maximum amount of adsorbate that can be adsorbed on a unit mass of adsorbent? (2020)
A.
Adsorption capacity
B.
Adsorption isotherm
C.
Saturation point
D.
Adsorption efficiency
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Solution
The maximum amount of adsorbate that can be adsorbed on a unit mass of adsorbent is referred to as the adsorption capacity.
Correct Answer: A — Adsorption capacity
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Q. What is the term for the maximum amount of solute that can be adsorbed on a given mass of adsorbent? (2023)
A.
Adsorption capacity
B.
Saturation point
C.
Equilibrium concentration
D.
Adsorption isotherm
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Solution
The maximum amount of solute that can be adsorbed on a given mass of adsorbent is referred to as the adsorption capacity.
Correct Answer: A — Adsorption capacity
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Q. What is the term used for the process of removing adsorbed molecules from a surface? (2020)
A.
Desorption
B.
Absorption
C.
Sorption
D.
Adsorption
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Solution
Desorption is the process of removing adsorbed molecules from a surface, while adsorption is the process of molecules adhering to a surface.
Correct Answer: A — Desorption
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Q. What is the trend in atomic radius as you move down the alkali metal group? (2022)
A.
Increases
B.
Decreases
C.
Remains constant
D.
Increases then decreases
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Solution
The atomic radius increases as you move down the alkali metal group due to the addition of electron shells.
Correct Answer: A — Increases
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Q. What is the trend in reactivity of alkali metals down the group? (2022)
A.
Increases
B.
Decreases
C.
Remains constant
D.
Varies irregularly
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Solution
The reactivity of alkali metals increases down the group due to the decrease in ionization energy.
Correct Answer: A — Increases
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