Free Thermochemistry and Energetics of Chemical Reactions MCQs with Answers
728 Thermochemistry and Energetics of Chemical Reactions MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Thermochemistry measures energy changes in chemical reactions and distinguishes exothermic from endothermic processes. Work covers systems, surroundings and state functions, internal energy, the first law of thermodynamics, enthalpy and Hess's law, including the sign conventions used when heat enters or leaves a system.
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728 questions · page 9 of 37
- A. thermochemistry
- B. thermodynamics
- C. chemical kinetics
- D. stoichiometry
Explanation: Explanation: Thermochemistry specifically deals with the study of energy changes in chemical systems.
Correct answer: thermochemistry- A. P.E +K.E
- B. P.E+heat enrgy
- C. K.E+heat energy
- D. P.E+mechanical
Explanation: Explanation: The total energy of a system is the sum of its potential energy (P.E) and kinetic energy (K.E).
Correct answer: P.E +K.E- A. delta H=qo
- B. delta E=q+w
- C. Delta E=q *v
- D. all of these
Explanation: Explanation: The first law of thermodynamics states that the change in internal energy (Delta E) of a system equals the heat added to the…
Correct answer: delta E=q+w164. CuSO4+Zn→ZnSO4+Cu is
- A. Spontaneous reaction
- B. non spontaneous
- C. Endothermic
- D. exothermic
Explanation: Explanation: This reaction involves the displacement of copper from copper sulfate by zinc, which occurs spontaneously as zinc is more…
Correct answer: Spontaneous reaction- A. -787KJ/mole.
- B. 787J/mole
- C. 780KJ/mole
- D. 790KJ/mole
Explanation: Explanation: The lattice energy of NaCl is typically around -787 kJ/mol, representing the energy released when gaseous ions combine to…
Correct answer: -787KJ/mole.- A. q=m x s x delta T
- B. q=delta T
- C. q=m x v x delta T
- D. q=pv
Explanation: Explanation: This equation represents the heat transferred (q) when a substance's temperature changes (delta T) with specific heat…
Correct answer: q=m x s x delta T- A. combustion
- B. formation of compound
- C. dissolution of ionic compound
- D. dilution of a solution
Explanation: Explanation: Dissolving an ionic compound in water often releases energy, resulting in a negative ΔH.
Correct answer: dissolution of ionic compound- A. both a & b
- B. delta H=Delta E
- C. delta H>Delta E
- D. both a and b
Explanation: Explanation: During the interconversion of states (solid to liquid or vice versa), there's usually a transfer of energy as heat (ΔH)…
Correct answer: delta H>Delta E- A. delta H lattice=delta Hf - delta Hx
- B. delta H lattice=delta Hf +delta Hx
- C. delta H lattice=delta a +delta v
- D. delta H lattice = delta H -delta sol
Explanation: Explanation: The enthalpy change for the formation of an ionic compound (ΔH lattice) equals the enthalpy change of formation of ions (ΔHf)…
Correct answer: delta H lattice=delta Hf +delta Hx- A. delta Hf
- B. Delta H latt
- C. detla H comb
- D. all of these
Explanation: Hess's law involves the principle that the total enthalpy change of a reaction is independent of the pathway taken and depends only on the…
Correct answer: all of these- A. 10%
- B. 16%
- C. 13%
- D. 25%
Explanation: The Haber process is an industrial method for the synthesis of ammonia (NH3) from nitrogen (N2) and hydrogen (H2) gases.
Correct answer: 16%- A. Al2O3
- B. Actinium oxide
- C. Cr2O3
- D. All of these
Explanation: Iron is indeed used as a catalyst in the synthesis of ammonia by the Haber process.
Correct answer: All of these- A. Unidirectional
- B. Reversible process
- C. Non-real process
- D. All of these
Explanation: Spontaneous reactions proceed in one direction only, from reactants to products, without the need for external intervention once…
Correct answer: Unidirectional- A. H2 > H1
- B. H1 > H2
- C. H1 = H2
- D. No relationship
Explanation: he information provided reveals two crucial aspects:The reaction is exothermic: The enthalpy change (ΔHc) is negative (-1368 kJ/mol).
Correct answer: H1 > H2- A. KOH and NaOH
- B. HCl and Ba(OH)2
- C. Ca(OH)2 and CH3COOH
- D. H2SO4 and KOH
Explanation: The enthalpy of neutralization is the heat evolved when an acid and a base react to form one mole of water under standard conditions…
Correct answer: HCl and Ba(OH)2- A. C
- B. Fe
- C. Pt
- D. Cu
Explanation: In a bomb calorimeter, the ignition coil is typically made of platinum (Pt).
Correct answer: Pt- A. ΔH = ΔE + PΔV
- B. q + w = ΔH
- C. ΔE = q - w
- D. ΔН +ΔЕ = w
Explanation: The first law of thermodynamics states that the total energy of a closed system remains constant.
Correct answer: ΔE = q - w- A. Unit
- B. Zero
- C. < zero
- D. Between Zero and one
Explanation: The enthalpies of free elements in their standard states are defined as zero.
Correct answer: Zero- A. Spontaneous and endothermic
- B. Spontaneous and exothermic
- C. Non-spontaneous and endothermic
- D. Non-spontaneous and exothermic
Explanation: The enthalpy of combustion of a substance refers to the heat released or absorbed when one mole of the substance undergoes complete…
Correct answer: Spontaneous and exothermic- A. -130.10 kJ
- B. -48.06 kJ
- C. +48.06 kJ
- D. +130.10 kJ
Explanation: We can use Hess's law to manipulate the given reactions and their enthalpy changes to arrive at the enthalpy change of formation of…
Correct answer: -130.10 kJ