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 515 of 686
- A. Enthalpy of formation
- B. Enthalpy of neutralization
- C. Enthalpy of Sublimation
- D. Enthalpy of reaction
Explanation: In the reaction above an acid base reaction is taking place which is also known as neutralisation with hydrogen ion from the acid reacting…
Correct answer: Enthalpy of neutralization- A. Entropy
- B. Enthalpy
- C. Internal energy
- D. Heat energy
Explanation: The total of all the possible kinds of energies in a system is called its internal energy including Kinetic energy and Potential energy.
Correct answer: Internal energy- A. Reaction conditions
- B. Concentration
- C. State of system
- D. All of these
Explanation: The state of a system is the condition of a system. SUPPOSE take a beaker.
Correct answer: State of system- A. Enthalpy change
- B. Surroundings
- C. Path of the reaction
- D. System
Explanation: State functions are independent of the path or process by which a system reaches a particular state.
Correct answer: Path of the reaction- A. Solid phase
- B. Gases phase
- C. Liquids, solids and solution
- D. None of these
Explanation: This is often the case for reactions that take place in open containers or in systems where the pressure remains relatively constant.
Correct answer: Liquids, solids and solution- A. Endothermic reactions
- B. Exothermic reactions
- C. Endergonic reactions
- D. Heat gaining reactions
Explanation: Option B "EXOTHERMIC REACTIONS" are those reactions in thermodynamics in which Heat is evolved or released (from system to surrounding)…
Correct answer: Exothermic reactions- A. Endothermic reaction
- B. Exothermic reaction
- C. Irreversible reaction
- D. Redox reaction
Explanation: An exothermic reaction is a chemical reaction that releases heat to its surroundings, resulting in an increase in temperature.
Correct answer: Exothermic reaction10288. The SI unit for work is _.
- A. Newtons
- B. Joule
- C. Newton/metre
- D. All of these
Explanation: The S.I unit of work is joule, work is also a form in which energy is transferred from one system to another.
Correct answer: Joule- A. 1st law
- B. 2nd law
- C. 3rd law
- D. None of these
Explanation: The statement reflects the 1st law of thermodynamics. The 1st law of thermodynamics, also known as the law of energy conservation, states…
Correct answer: 1st law- A. q=m s ∆T
- B. E=q m ∆T
- C. E=m s ∆T
- D. q=m e ∆T
Explanation: q = m * s * ∆T is correct It takes into account the mass of the solution, the specific heat capacity of the solution, and the change in…
Correct answer: q=m s ∆T10291. Heat exchanged between the system and surrounding at constant volume is shown by the relation:
- A. ∆H= qv+ w
- B. ∆E= (q)v
- C. ∆H=(q)v
- D. ∆E= (q)v + PV
Explanation: ΔE= q - ΔW ΔE = q - PΔV Where ΔE = change in internal energy q= heat ΔW = work done P = pressure ΔV = volume The equation becomes , q = ΔE…
Correct answer: ∆E= (q)v- A. Entropy
- B. Work function
- C. Total heat content
- D. Internal energy
Explanation: Enthalpy is the measurement of energy in a thermodynamic system. The quantity of enthalpy equals to the total content of heat of a system…
Correct answer: Total heat content- A. Second law of thermodynamics
- B. Third law of thermodynamics
- C. First law of thermodynamics
- D. Zeroth law of thermodynamics
Explanation: The correct answer is the First Law of Thermodynamics, which directly restates the Law of Conservation of Energy.
Correct answer: First law of thermodynamics- A. ∆G
- B. ∆H
- C. ∆E
- D. ∆H-∆E
Explanation: Delta G (ΔG) represents the change in Gibbs free energy of a chemical reaction or a physical process The heat absorbed by a substance at…
Correct answer: ∆H- A. Enthalpy of formation
- B. Enthalpy of combustion
- C. Enthalpy of neutralization
- D. Enthalpy of sublimation
Explanation: The standard enthalpy of formation of a compound is the amount of heat absorbed or evolved (enthalpy change) when one mole of a compound…
Correct answer: Enthalpy of formation- A. Gases
- B. Liquids
- C. Liquids and solids
- D. Liquids and Gases
Explanation: In the case of solids and liquids, the changes in the state do not cause significant volume change, i.e ΔV = 0.
Correct answer: Liquids and solids- A. 15 Kj/mol
- B. -17kJ/mol
- C. 16.2 kJ/mol
- D. -16.5 kJ/mol
Explanation: Remember that the enthalpy of solution of NH4Cl is +16.2 kJ/mol.
Correct answer: 16.2 kJ/mol- A. Endothermic reaction
- B. Exothermic reaction
- C. Spontaneous reaction
- D. Chemical reaction
Explanation: Evaporation of water is an endothermic reaction. During evaporation, water molecules absorb heat from the surroundings and change into…
Correct answer: Endothermic reaction- A. 11RT
- B. 4RT
- C. 5RT
- D. 7RT
Explanation: The formula of internal energy is U = (nRTf)/ 2where n = number of moles of the gas, f = number of degree of freedom.Keep in mind that…
Correct answer: 11RT- A. 5/3
- B. 1.3
- C. 4/3
- D. 7/5
Explanation: The heat capacity ratio of a gas is the ratio Cp and Cv. γ = Cp/Cv
Correct answer: 5/3