All Free Chemistry MCQs with Answers

• A. -110 kJ/mol
• B. -210 kJ/mol
• C. -111 kJ/mol
• D. None of these options is correct

Explanation: By constructing a Hess' Cycle for CO along with the relevant data given relating to the standard enthalpy change of formation of CO2 and…

• A. ΔE = ΔH
• B. ΔE = q + p
• C. ΔE = q+w
• D. ΔE = -PΔV

Explanation: The first law of thermodynamics is given as ΔE=q+w, where ΔE is the change in internal energy of a system, q is the net heat transfer (the…

• A. 200 atm
• B. 25 atm
• C. 20 atm
• D. 75 atm

Explanation: High-Pressure oxygen is required to ensure the sample burns completely in the bomb vessel.

• A. Enthalpy change
• B. Free energy of the system
• C. Energy Change
• D. Temperature Change

Explanation: Free energy of the system also known as the Gibbs free energy determines if the reaction is spontaneous or not.

• A. Vibrational
• B. Translational
• C. Rotational
• D. Static

Explanation: Kinetic energy needs an object to be in motion.

• A. Highly exothermic
• B. Slightly endothermic
• C. Zero
• D. Slightly exothermic

Explanation: The heat of solution for NaCl is slightly endothermic which allows for its dissolution spontaneousy in water since the increase in entropy…

• A. Exothermic reaction
• B. Endothermic reaction
• C. Spontaneous reaction
• D. Nonspontaneous reaction

Explanation: In a combustion reaction, heat is always given off as the compound burns in excess oxygen to given carbon dioxide.

• A. Initial condition of the system
• B. Final condition of the system
• C. Path of the system
• D. Both initial and final conditions of the system

Explanation: STATE FUNCTION:A state function is the property of the system that depends on the initial and final states and is independent of the path…

• A. Addition Reaction
• B. Substitution Reaction
• C. Neutralization Reaction
• D. Reversible Reaction

Explanation: OPTION A: Addition reaction occurs when two or more reactants combine to form a product without the loss of any atoms present in the…

• A. Reversible Reaction
• B. Spontaneous Reaction
• C. Endothermic Reaction
• D. All of these options are correct

Explanation: OPTION A: The reactions that do not go to completion and the products formed react to re-form the reactants are called reversible…

• A. W = P V
• B. W = ΔP V
• C. W = P ΔV
• D. W = P + ΔV

Explanation: W = P ΔVThis is called pressure-volume work and is positive when it is done on the system.

• A. Microscopic
• B. Dependent
• C. Macroscopic
• D. Constant

Explanation: A state function is a macroscopic property of a system which has some definite values for initial and final states, which is independent…

• A. Constant
• B. Variable
• C. Depends on the strength of acid
• D. Depends on the strength of base

Explanation: The enthalpy of neutralization of all strong acids and strong bases is always constant i.e. -57.1 kJ.

• A. System
• B. Surroundings
• C. Boundary
• D. None of These

Explanation: The correct answer is Boundary. In thermochemistry, the piston in the cylinder serves as a boundary that separates the system from its…

• A. Evaporation
• B. Fusion
• C. Sublimation
• D. Respiration

Explanation: Exothermic processes generate heat, which raises the heat from the surrounding environment.

• A. Electrochemistry
• B. Biochemistry
• C. Thermochemistry
• D. Analytical Chemistry

Explanation: Thermochemistry is the study of the heat energy which is associated with chemical reactions and/or phase changes such as melting and…

• A. Endothermic reactions
• B. Exothermic reactions
• C. Exergonic reactions
• D. Heat releasing reactions

Explanation: Endothermic reactions are those reactions which requires heat or energy from surrounding.When an endothermic reaction occurs, the heat…

• A. Temperature (T)
• B. Volume (V)
• C. Enthalpy (E)
• D. Heat (q)

Explanation: Heat is NOT a state function. Heat is the transfer of energy between a system and its surroundings due to a temperature difference.

• A. Heat
• B. Energy
• C. Work
• D. All of these

Explanation: Heat is measured in joules. The energy units in which heat changes, usually expressed in SI system are joule (J) and kilojoule (kJ).

• A. Born Haber cycle
• B. Joule's principle
• C. Hess's law
• D. Law of conservation of energy

Explanation: Hess's Law states that the overall enthalpy change of a reaction is independent of the pathway followed as long as the initial and final…