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 521 of 686
- A. It is an endothermic process
- B. It can be represented as H3O+(aq)+ OH.(aq) → 2H2O(I)
- C. The enthalpy change per mole of H2O formed is independent of the acid or alkali used as they are strong
- D. Both B and C
Explanation: C is true. Standard enthalpy change of neutralization is approximately the same for every strong base and strong acid i.e. -57.4 kJmol-1
Correct answer: The enthalpy change per mole of H2O formed is independent of the acid or alkali used as they are strong- A. A
- B. B
- C. C
- D. D
Explanation: B is correct. The energy of products should be greater than that of reactants in an endothermic reaction.
Correct answer: B10403. Lattice energy (∆H∘latt) helps to explain all of the following properties of ionic compounds EXCEPT:
- A. Structure
- B. Heat of solution
- C. Bonding
- D. Dipole Moment
Explanation: Lattice energy can not explain the dipole moment of ionic compounds. Ionic compounds are held tight in a giant lattice, so the…
Correct answer: Dipole Moment- A. The study of heat changes accompanying a chemical reaction is known as thermochemistry
- B. Thermodynamics is a branch of physics that deals with heat, work and temperature
- C. Both A and B
- D. Neither A nor B
Explanation: Option C is correct because both statements A and B are accurate descriptions of thermochemistry and thermodynamics.
Correct answer: Both A and B- A. CCI4
- B. Al2O3
- C. B2O3
- D. MgO
Explanation: Option D, MgO (magnesium oxide), is correct because its standard enthalpy change (∆H∘) can be measured directly by a…
Correct answer: MgO- A. ∆Hv
- B. ∆H°sol
- C. ∆H°BDE
- D. ∆Hi
Explanation: Option B, ∆H°sol, refers to the standard enthalpy change of solution, which is the enthalpy change when one mole of a substance dissolves…
Correct answer: ∆H°sol- A. ∆H°n
- B. ∆H°at
- C. ∆H°sol
- D. ∆H°f
Explanation: Option A, "∆H°n," is correct because a glass calorimeter is typically used to measure the heat of a chemical reaction at constant…
Correct answer: ∆H°n- A. Remains constant
- B. Decreases
- C. Increases
- D. Remains unchanged
Explanation: Option b is correct because in an endothermic reaction, heat is absorbed from the surroundings, causing a decrease in temperature.
Correct answer: Decreases- A. A
- B. B
- C. C
- D. D
Explanation: Option d is correct because it makes an inaccurate generalization about the relative magnitudes of qv and qp without specifying the…
Correct answer: D- A. A
- B. B
- C. C
- D. D
Explanation: The term system is used for anything (materials) under test in the laboratory, or under consideration in the classroom for the purpose of…
Correct answer: B- A. Temperature
- B. Physical state of reactants and products
- C. Reaction conditions
- D. All of these
Explanation: The temperature at which a reaction occurs significantly affects the heat of reaction.
Correct answer: All of these- A. Chemical nature of a substance
- B. Temperature
- C. Pressure and volume
- D. Path
Explanation: In thermodynamics, the internal energy of a system is a state function, which means it depends only on the initial and final states of the…
Correct answer: Path- A. ∆H°f > ∆Hhyd
- B. ∆Hhyd > ∆H°f
- C. ∆Hhyd = ∆H°f
- D. ∆Hhyd ≤ ∆H°f
Explanation: For an ionic solid to dissolve in water, it must overcome the energy barrier associated with breaking the ionic bonds in the solid and the…
Correct answer: ∆Hhyd > ∆H°f- A. To study processes at constant volume (∆V = 0) only
- B. To study processes at constant pressure (∆P = 0) only
- C. Both A and B
- D. Neither A nor B
Explanation: To study processes at constant volume (∆V = 0): The first law of thermodynamics is applicable to processes that occur at constant volume.
Correct answer: Both A and B- A. Law of mass action
- B. Hess's Law
- C. Joule's Law
- D. First law of thermodynamics
Explanation: This statement is related to Hess's law which states that: "If a chemical change takes place by several different routes, the overall…
Correct answer: Hess's Law- A. ∆Hlatt = ∆Hf - ∆Hx
- B. ∆Hlatt = ∆Hx - ∆Hf
- C. ∆Hlatt = ∆Hx + ∆Hf
- D. ∆Hlatt = ∆Ha - ∆Hx
Explanation: The lattice energy, gives us some idea of the force of attraction between Na+ and Cl- ions in crystalline sodium chloride.
Correct answer: ∆Hlatt = ∆Hf - ∆Hx- A. State
- B. State function
- C. Surrounding
- D. System
Explanation: The macroscopic property of a system that has definite values for the initial and final states and is independent of the path taken to…
Correct answer: State function10418. To predict whether the reaction is spontaneous or non-spontaneous it is based on the value of:
- A. ∆H
- B. ∆E
- C. ∆T
- D. ∆G
Explanation: Based on the information provided, the correct option for predicting whether the reaction is spontaneous or non-spontaneous is ∆G.
Correct answer: ∆G- A. 270K
- B. 200K
- C. 298K
- D. 273K
Explanation: The correct option for the temperature at which the standard enthalpy change is measured is C) 298K (Kelvin).
Correct answer: 298K- A. State of the system may change
- B. Temperature of the system may change
- C. Chemical reaction may take place
- D. Route of the system may change
Explanation: When the internal energy of a system increases, several changes can indeed take place, but the "route" of the system is not one of them.
Correct answer: Route of the system may change