For an exothermic reaction (A) Only enthalpy change (ΔH) is negative (B) Only internal energy change (ΔE) is negative (C) Both ΔH and ΔE are negative (D) Enthalpy change is zero

For an exothermic reaction
(A) Only enthalpy change (ΔH) is negative
(B) Only internal energy change (ΔE) is negative
(C) Both ΔH and ΔE are negative
(D) Enthalpy change is zero
by

1 Answer

Answer :

(C) Both ΔH and ΔE are negative
by

Related questions

For an isothermal reversible compression of an ideal gas (A) Only ΔE = 0 (B) Only ΔH =0 (C) ΔE = ΔH = 0 (D) dQ = dE

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Last Answer : C) ΔE = ΔH = 0

In a totally irreversible isothermal expansion process for an ideal gas, ΔE = 0, ΔH = 0. Then ΔQ and ΔS will be (A) ΔQ = 0, ΔS=0 (B) ΔQ = 0, ΔS = +ve (C) ΔQ = 0, ΔS = -ve (D) ΔQ = +ve, ΔS= +ve

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Last Answer : (B) ΔQ = 0, ΔS = +ve

In the reaction, C + O2 → CO2; ΔH = - 94 kcal. What is the heat content (enthalpy) of O2? (A) -94 kcal (B) > -94 kcal (C) < - 94 kcal (D) Zero

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The ammonia synthesis reaction represented by N2 + 3H2 ⇌ 2NH3; ΔH = - 22.4 kcal, is (A) Endothermic (B) Exothermic (C) Isothermal (D) Adiabatic

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For a constant pressure reversible process, the enthalpy change (ΔH) of the system is (A) Cv.dT (B) Cp.dT (C) ∫ Cp.dT (D) ∫ Cv.dT

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High pressure steam is expanded adiabatically and reversibly through a well insulated turbine, which produces some shaft work. If the enthalpy change and entropy change across the turbine are represented by ΔH and ΔS respectively for this process: (A) Δ H = 0 and ΔS = 0 (B) Δ H ≠ 0 and ΔS = 0 (C) Δ H ≠ 0 and ΔS ≠ 0 (D) Δ H = 0 and ΔS ≠ 0

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Last Answer : (D) Not possible to predict

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In the reaction, represented by, 2SO2 + O2 ⇌ 2SO3; ΔH = - 42 kcal; the forward reaction will be favoured by (A) Low temperature (B) High pressure (C) Both (A) and (B) (D) Neither (A) nor (B)

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An ideal gas is compresses isothermally. The enthalpy change is  a. Always negative  b. Always positive  c. zero  d. undefined

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Consider the reaction, C + O2 ⇌ CO2; ΔH = - 94 kcal. What will be the value of ΔH for the reaction CO2 → C + O2? (A) -94 kcal (B) +94 kcal (C) > 94 kcal (D) < -94 kcal

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Einstein's mass-energy relationship states that if the mass decreases by Δm, the energy released ΔE is given by A. ΔE = Δm × c, where "c" denotes the speed of light. B. ΔE = Δm × c², where "c" denotes the speed of light. C. ΔE = Δm ⁄ c, where "c" denotes the speed of light. D. ΔE = Δm ⁄ c², where "c" denotes the speed of light

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From the elements: Cl, Br, F, O, Al, C, Li, Cs and Xe; choose the following: (a) The element with highest negative electron gain enthalpy. (b) The element with lowest ionization enthalpy. (c) The element with smallest ionic radius. (d) The element with six electrons in the valence shell. (e) The element which is a liquid at room temperature. (f)The element which belongs to zero group. (g) The elements which forms largest number of compounds.

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For an incompressible fluid, the __________ is a function of both pressure as well as temperature. (A) Internal energy (B) Enthalpy (C) Entropy (D) All (A), (B) & (C)

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When ΔH>0 and ΔS< 0, reaction is never spontaneous. Explain.

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Pick out the wrong statement. (A) Enthalpies of all elements in their standard states are assumed to be zero (B) Combustion reactions are never endothermic in nature (C) Heat of reaction at constant volume is equal to the change in internal energy (D) Clausius-Clapeyron equation is not applicable to melting process

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Entropy is the measure of:  a. The internal energy of a gas  b. The heat capacity of a substance  c. Randomness or disorder  d. The change of enthalpy of a system

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Which of the following occurs in a reversible polytrophic process?  a. Enthalpy remains constant  b. Internal energy does not change  c. Some heat transfer occurs  d. Entropy remains constant

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In an isothermal process,  A. there is no change in temperature  B. there is no change in enthalpy  C. there is no change in internal energy  D. all of these

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Last Answer : Answer: D

If heat be exchanged in a reversible manner, which of the following property of the working substance will change accordingly  (a) temperature  (b) enthalpy  (c) internal energy  (d) entropy  (e) all of the above.

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Last Answer : Answer : d

Change in enthalpy in a closed system is equal to heat transferred if the reversible process takes place at constant  (a) pressure  (b) temperature  (c) volume  (d) internal energy  (e) entropy.

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Last Answer : Answer : a

For which of the following substances, the internal energy and enthalpy are the functions of temperature only  (a) any gas  (b) saturated steam  (c) water  (d) perfect gas  (e) superheated steam.

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Last Answer : Answer : d

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Photochemical reaction rate does not depend significantly on temperature, because (A) It is a reversible reaction (B) It is an exothermic reaction (C) The energy of reacting molecules exceeds the activation energy by absorption of light (D) None of these

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In an exothermic reaction, the energy of the reacting substances as compared to that of products is (A) More (B) Less (C) Same (D) Either (A) or (B), depends on order of reaction

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If an ideal solution is formed by mixing two pure liquids in any proportion, then the __________ of mixing is zero (A) Enthalpy (B) Volume (C) Both 'a' & 'b' (D) Neither 'a' nor 'b'

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For the reversible exothermic reaction, N2 + 3H2 ⇌ 2NH3, increase of pressure would (A) Shift the equilibrium towards right (B) Give higher yield of NH3 (C) Both (B) and (C) (D) Neither (A) nor (B)

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What are the names given to constant temperature, constant pressure, constant volume, constant internal energy, constant enthalpy, and constant entropy processes.

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Last Answer : Isothermal, isochroic, isobaric, free expression, throttling and adiabatic processes respectively.