All Free Chemistry MCQs with Answers
Every Chemistry question in the bank, across all chapters, each with the correct answer and a written explanation. Free and unlimited, with no account needed.
13,720 questions · page 513 of 686
- A. Activation Energy
- B. Internal energy change
- C. Entropy
- D. Enthalpy
Explanation: Enthalpy is the measure of total heat present in a system under constant pressure. It takes into account both internal and external heat.
Correct answer: Enthalpy- A. Charge to size ratio
- B. Polarizability of anions
- C. Polarization power of Cations
- D. All of these
Explanation: Hydration energy is the amount of energy released or absorbed when ions in gaseous state are surrounded by water molecules to form…
Correct answer: All of these- A. By spectrometry
- B. By conductometry
- C. By calorimetry
- D. By refractometry
Explanation: Calorimetry is used to measure amounts of heat change.
Correct answer: By calorimetry- A. Entropy
- B. Heat
- C. Enthalpy
- D. Temperature
Explanation: Correct option is C. Enthalpy, a property of a thermodynamic system, is the sum of the system's internal energy and the product of its…
Correct answer: Enthalpy- A. Latent heat of fusion
- B. Latent heat of vaporization
- C. Latent heat of sublimation
- D. All of these
Explanation: Correct option is B. This option is correct because steam has more warmth and vitality than water.
Correct answer: Latent heat of vaporization- A. System
- B. Surroundings
- C. Boundary
- D. Universe
Explanation: Endothermic reactions are the ones that need the energy to proceed. This energy in the form of heat is absorbed from the surroundings.
Correct answer: Surroundings- A. Nitrogen gas
- B. Ethene
- C. Water
- D. All have the same heat of vaporization
Explanation: The heat of vaporization is defined as the amount of heat required to convert 1g of a liquid into vapors, without any change in…
Correct answer: Water- A. Mg⁺²
- B. Ca⁺²
- C. Be⁺²
- D. Sr⁺²
Explanation: The hydration enthalpy becomes smaller as the size of the ion increases.
Correct answer: Be⁺²- A. 273 K
- B. 212 F
- C. 273 C
- D. 298 K
Explanation: Bond enthalpy is the energy change at 25 oC or 298 K.
Correct answer: 298 K- A. Work done
- B. Entropy
- C. Potential energy
- D. Kinetic energy
Explanation: The correct option is A) Work done. Enthalpy is the sum of internal energy and the work done on or by the system.
Correct answer: Work done- A. Initial conditions
- B. Final conditions
- C. Initial and final conditions
- D. Path of the reaction
Explanation: Volume is a state funtion which means that it depends only on the the initial and final conditions and is independent of the path followed.
Correct answer: Initial and final conditions- A. 1
- B. 10
- C. 1/e
- D. 2.718
Explanation: ∆rGº = - 8.314 × 103∴- ∆rGº = 8.314 × 103 = RT ln Keqor 8.314 × 103 = 8.314 × 103 ln Keqor ln Keq = 1 = ln e or Keq = e = 2.718
Correct answer: 2.718- A. -143 KJ
- B. -286 KJ
- C. Zero
- D. +286 KJ
Explanation: The calorific value of H2(g) at STP is given as 12.78 kJ/L. At STP, 1 mole of gas occupies 22.4 L.
Correct answer: -286 KJ- A. Buffer
- B. Transition Zone
- C. Boundary
- D. Intermediate state
Explanation: Option A: A buffer is a solution that helps maintain a stable pH level by resisting changes in acidity or alkalinity.
Correct answer: Boundary- A. Total energy
- B. Kinetic Energy
- C. Potential Energy
- D. Internal Energy
Explanation: Internal energy is defined as the total energy of a closed system.
Correct answer: Internal Energy- A. NA+ R
- B. R/NA
- C. NA/R
- D. NA*R
Explanation: The Boltzmann constant (k or k_B) is a physical constant that relates the average kinetic energy of particles in a gas with the…
Correct answer: R/NA- A. Energy content of product is more
- B. Energy content of reactant is less
- C. Heat is transferred from the system to surrounding
- D. Heat is transferred from the Surrounding to the system
Explanation: The correct option is C) Heat is transferred from the system to surrounding.
Correct answer: Heat is transferred from the system to surrounding- A. Spontaneous Reaction
- B. Exothermic Reaction
- C. Reversible Reaction
- D. Endothermic Reaction
Explanation: The correct answer is Endothermic Reaction. The conversion of water into steam involves the absorption of heat energy to overcome the…
Correct answer: Endothermic Reaction- A. Surrounding from the environment
- B. Reactants from contamination
- C. System from surrounding
- D. Products from the surrounding
Explanation: By definition, the real or imaginary surface separating the system from the surroundings is called the boundary.
Correct answer: System from surrounding10260. The property of the system which does not depend upon the path followed by the system is called as?
- A. State function
- B. Path function
- C. Dependent function
- D. Independent function
Explanation: A state function is a macroscopic property of a system which has some definite values for initial and final states, and which is…
Correct answer: State function