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 527 of 686
- A. (y - 2x)
- B. (x + y)
- C. (2x -y)
- D. 2x/y
Explanation: Reverse the second reaction and change the sign of its enthalpy change: SO3(g) + y kJ → SO2(g) + 1/2 O2(g) Multiply the first reaction by…
Correct answer: (2x -y)- A. Isolated system
- B. Open system
- C. Adiabatic system
- D. Closed system
Explanation: Both energy and mass are transferrable, therefore option B is correct.
Correct answer: Open system- A. 30J
- B. 40 J
- C. 50 J
- D. 20 J
Explanation: To find the increase in internal energy of the system, we can use the first law of thermodynamics, which states: ΔU = Q - W where: ΔU =…
Correct answer: 30J- A. Increased
- B. Decreased
- C. Neither increased nor decreased
- D. First increases and then decreases
Explanation: Option A is correct because the energy of the system during endothermic reactions is increased as it absorbs heat.
Correct answer: Increased- A. Heat capacity
- B. Specific heat
- C. External energy
- D. Internal energy
Explanation: Option D is correct because internal energy includes both kinetic energy, which arises from the random movement of particles, and…
Correct answer: Internal energy- A. Vibrational movements
- B. Translational movements
- C. Rotational movements
- D. All of them
Explanation: Option D is correct as in solid substances, particles are arranged in a fixed lattice, and they vibrate around their equilibrium…
Correct answer: All of them- A. -228.88KJ
- B. -343.52KJ
- C. +228.88kJ
- D. -22.88KJ
Explanation: "The explanation for this question will be added soon!"
Correct answer: -228.88KJ10528. Solid particles exhibit:
- A. Vibrational movement
- B. Rotational movement
- C. Translational movement
- D. No potential energy
Explanation: Option A is correct because in solid substances, particles are arranged in a fixed lattice, and they vibrate around their equilibrium…
Correct answer: Vibrational movement- A. ∆ E = q w
- B. ∆ E = qv
- C. ∆ E = q + P ∆ V
- D. ∆ E = qp
Explanation: At constant volume no work is done and the entire heat supplied is converted to internal energy ,thus option B is correct.
Correct answer: ∆ E = qv- A. 14
- B. 25
- C. 28
- D. 38
Explanation: One angle of a triangle is 82 °. The other two angles are in the ratio 2:5.
Correct answer: 28- A. When 1 mole of Zn is dissolved in excess HCl, the work done is approximately equal to -2.46 kJ in an open beaker at 300 K and 1 atm.
- B. When 1 mole of Zn is dissolved in excess HCl, the work done is zero in a closed beaker.
- C. Both (a) and (b) are correct.
- D. Neither (a) nor (b) are correct.
Explanation: The correct answer is Option C: Both (a) and (b) are correct. In an open beaker, when zinc reacts with hydrochloric acid, work is done as…
Correct answer: Both (a) and (b) are correct.- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: The correct answer is Option A because it correctly calculates the specific heat at constant pressure per gram of gas using the given…
Correct answer: Option A- A. ΔHf = x1+ 3x2 - 6x3
- B. ΔHf = 3x3 - 1/2x1 - 3/2 x2
- C. ΔHf = x1/2 + 3/2x2 - 3x3
- D. ΔHf = 6x3 - x1 - 3x2
Explanation: To find the enthalpy of formation (ΔHf) of NH3, consider the bond dissociation energies: The formation of NH3 from N2 and H2 involves…
Correct answer: ΔHf = x1/2 + 3/2x2 - 3x3- A. 100 mol
- B. 10 mol
- C. 20 mol
- D. 200 mol
Explanation: The formation of glucose from CO2 and H2O in plant cells is a non-spontaneous process with a Gibbs free energy change of 3000 kJ/mol…
Correct answer: 100 mol- A. 0.75 atm
- B. 2 atm
- C. 2.5 atm
- D. 0.5 atm
Explanation: In an adiabatic process for an ideal monoatomic gas, the relationship between pressure and temperature is given by the equation…
Correct answer: 0.75 atm- A. Energy can neither be created nor destroyed
- B. One form of energy can be converted into another form of energy
- C. In an adiabatic process, the work done is independent of its path
- D. Continuous production of mechanical work without supplying an equivalent amount of heat is possible
Explanation: The first law of thermodynamics, or the law of conservation of energy, states that energy cannot be created or destroyed, only transformed…
Correct answer: Continuous production of mechanical work without supplying an equivalent amount of heat is possible- A. Heat lost by the system
- B. Work done on the system
- C. Work done by the system
- D. Positive ∆E when heat is lost by the system
Explanation: OPTION A: Heat lost by the system is considered to have a negative value in thermodynamics.
Correct answer: Work done on the system- A. Internal energy
- B. Volume
- C. Work
- D. Enthalpy
Explanation: The correct answer is Option C: Work. Work is not a state function because it depends on the specific process or path taken to change the…
Correct answer: Work- A. 40 kJ
- B. 10 kJ
- C. 20 kJ
- D. 0 kJ
Explanation: In thermochemistry, when a process occurs at constant volume, no work is done on or by the system because work is defined as W = -PΔV…
Correct answer: 0 kJ10540. I k cal is equal to
- A. 41.8 x 10^3 J
- B. 418 x 10^3 J
- C. 4.18 x 10^3 J
- D. 0.418 x 10^3 J
Explanation: The correct conversion factor between calories and joules is 1 cal = 4.18 J.
Correct answer: 4.18 x 10^3 J