Description : The value of enthalpy change `(DeltaH)` for the reaction `C_(2)H_(5)OH (l)+3O_(2) (g) rarr 2CO_(2) (g) +3H_(2)O (l)` at `27^(@)C` is `-1366.5 kJ mol^(
Last Answer : The value of enthalpy change `(DeltaH)` for the reaction `C_(2)H_(5)OH (l)+3O_(2) (g) rarr 2CO_(2) (g) + ... 1369. kJ` C. `-1364.0 kJ` D. `-1361.5 kJ`
Description : The enthalpy change for a given reaction at `298 K` is `-x cal mol^(-1)`. If the reaction occurs spontaneously at `298 K`, the entropy change at that
Last Answer : The enthalpy change for a given reaction at `298 K` is `-x cal mol^(-1)`. If the reaction occurs ... (-1)` C. Cannot be negative D. Cannot be positive
Description : The enthalpy of formation of `CO(g), CO_(2)(g),N_(2)O(g)` and `N_(2)O_(4)(g)` is `-110,-393,+81` and 10 kJ / mol respectively. For the reaction `N_(2)
Last Answer : The enthalpy of formation of `CO(g), CO_(2)(g),N_(2)O(g)` and `N_(2)O_(4)(g)` is `-110,-393,+81` and 10 ... is A. `-212` B. `+212` C. `+778` D. `-778`
Description : `Delta_(f)^(@)` for `CO_(2(g)), CO_((g))` and `H_(2)O_((g))` are `-393.5,-110.5` and `-241.8kJ mol^(-1)` respectively. The standard enthalpy change `(
Last Answer : `Delta_(f)^(@)` for `CO_(2(g)), CO_((g))` and `H_(2)O_((g))` are `-393.5,-110.5` and `-241.8kJ mol^(-1 ... A. `524.1` B. `41.2` C. `-262.5` D. `-41.2`
Description : If a reaction has an enthalpy of -54.32 kJ/mol and an entropy of -354.2 J/(K*mol), what is the Gibbs free Energy at 54.3(degrees c)?
Last Answer : DeltaG = DeltaH - TDeltaS dG = -54.32 kJ/mol - (54'32+273)K(-354.2J/molK) NB Thevtemperature is quoted in Kelvin(K) and the Entropy must be converted to kJ by dividing by '1000'/ Hence dG = ... 115.94 kJ/mol dG = (+)61.61 kJ/mol Since dG is positive, the reaction is NOT thermodynamically feasible.
Description : The bond energies of `F_(2),Cl_(2),Br_(2)` and `I_(2)` are 155.4, 243.6, 193.2 and `151.2 Kjmol^(-1)` respectively. The strongest bond is :
Last Answer : The bond energies of `F_(2),Cl_(2),Br_(2)` and `I_(2)` are 155.4, 243.6, 193.2 and `151.2 Kjmol^(-1)` ... . F -F B. Cl - Cl C. Br - Br D. I - I
Description : The enthalpy of formation of ammonia is `-46.0 KJ mol^(-1)` . The enthalpy change for the reaction `2NH_(3)(g)rarr N_(2)(g)+3H_(2)(g)` is :
Last Answer : The enthalpy of formation of ammonia is `-46.0 KJ mol^(-1)` . The enthalpy change for the reaction `2NH_(3)(g) ... mol^(-1)` D. `-92.0 KJ mol^(-1)`
Description : Calculate the entropy of `Br_(2)(g)` in the reaction `H_(2)(g)+Br_(2)(g)rarr2HBr(g), Delta S^(@)=20.1 JK^(-1)` given, entropy of `H_(2)` and HBr is 13
Last Answer : Calculate the entropy of `Br_(2)(g)` in the reaction `H_(2)(g)+Br_(2)(g)rarr2HBr(g), Delta S^(@)=20.1 JK^(-1 ... ` C. `24.63 JK^(-1)` D. `20 KJK^(-1)`
Description : If the enthalpy of vaporisation of water is `186.5 J mol^(-1)`, then entropy of its vaporisation will be
Last Answer : If the enthalpy of vaporisation of water is `186.5 J mol^(-1)`, then entropy of its vaporisation will be A. `0.5 ... (-1)` D. `2.0KJK^(-1)"mole"^(-1)`
Description : `CH_(3)-CH_(2)-CH_(2)-underset(OH)underset(|)(CH)-CH_(3) underset(-H_(2)O)overset(H^(o+))rarr[F] overset(Br_(2)//C Cl_(4))rarrC_(5)H_(10)Br_(2)(G)` Ho
Last Answer : `CH_(3)-CH_(2)-CH_(2)-underset(OH)underset(|)(CH)-CH_(3) underset(-H_(2)O)overset(H^(o+))rarr[F] ... (including all stereoisomers) A. 2 B. 6 C. 3 D. 5
Description : Standard entropy of `X_(2)` , `Y_(2)` and `XY_(3)` are `60, 40 ` and `50JK^(-1)mol^(-1)` , respectively. For the reaction, `(1)/(2)X_(2)+(3)/(2)Y_(2)r
Last Answer : Standard entropy of `X_(2)` , `Y_(2)` and `XY_(3)` are `60, 40 ` and `50JK^(-1)mol^(-1)` , respectively ... be: A. 500 K B. 750 K C. 1000 K D. 1250 K
Description : Bond dissociation enthalpy of `H_(2)` , `Cl_(2)` and `HCl` are `434, 242` and `431KJmol^(-1)` respectively. Enthalpy of formation of `HCl` is
Last Answer : Bond dissociation enthalpy of `H_(2)` , `Cl_(2)` and `HCl` are `434, 242` and `431KJmol^(-1)` respectively. ... kJ mol^(-1)` D. `-245 kJ mol^(-1)`
Description : 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: ... (C) Δ H ≠ 0 and ΔS ≠ 0 (D) Δ H = 0 and ΔS ≠ 0
Last Answer : (B) Δ H ≠ 0 and ΔS = 0
Description : Specific __________ does not change during a phase change (e.g. sublimation, melting, vaporisation etc.). (A) Entropy (B) Internal energy (C) Enthalpy (D) Gibbs free energy
Last Answer : (D) Gibbs free energy
Description : The enthalpy changes at 298 K in successive breaking of `O-H` bonds of water, are `H_(2)O(g) rarr H(g)+OH(g),DeltaH=498kJ mol^(-1)` `OH(g) rarr H(g)+O
Last Answer : The enthalpy changes at 298 K in successive breaking of `O-H` bonds of water, are `H_(2)O(g) rarr H(g)+OH(g), ... KJ mol"^(-1)` D. `463 "KJ mol"^(-1)`
Description : The acid D obtained through the following sequence of reactions is: `C_(2)H_(5)Br overset(Alc. KOH)rarrA overset(Br_(2))underset(C Cl_(4))rarrBoverset
Last Answer : The acid D obtained through the following sequence of reactions is: `C_(2)H_(5)Br overset(Alc. KOH) ... B. Malonic acid C. Maleic acid D. Oxalic acid
Description : The type of isomerism that `Co(NH_(3))_(4)Br_(2)Cl_(2)` can exhibit is/are
Last Answer : The type of isomerism that `Co(NH_(3))_(4)Br_(2)Cl_(2)` can exhibit is/are A. ... C. Optical and ionisation D. Optical, ionisation and geometric
Description : Compound (A), `C_(10)H_(12)O` gives off hydrogen on treatment with sodium metal and decolourises `Br_(2)` in `C Cl_(4)` to give (B), `C_(10)H_(12)OBr`
Last Answer : Compound (A), `C_(10)H_(12)O` gives off hydrogen on treatment with sodium metal and ... pairs of diasteereomers D. A has 2 chiral centres
Description : A `C_(6)H_(12)O` compound does not react with `Br_(2)` in `C Cl_(4)`, produces a flammable gas on treatment with `LiAlH_(4)`, and reacts with `H_(2)Cr
Last Answer : A `C_(6)H_(12)O` compound does not react with `Br_(2)` in `C Cl_(4)`, ... B. methoxycyclopentane C. 2-cyclopropyl-2-propanol D. 2-cyclobutylethanol
Description : For a reaction `2X(s)+2Y(s)rarr 2Cl(l)+D(g)` The `q_(p)` at `27^(@)C` is -28 K Cal. `mol^(-1)`. The `q_(V)` is ___________ K. Cal. `mol^(-1)` :-
Last Answer : For a reaction `2X(s)+2Y(s)rarr 2Cl(l)+D(g)` The `q_(p)` at `27^(@)C` is -28 K Cal. `mol^(-1)`. The `q_( ... . `-27.4` B. `+27.4` C. `-28.6` D. `28.6`
Description : What is meant by entropy driven reaction? How can the reaction with positive change of enthalpy and entropy be made entropy driven?
Last Answer : Ans.The free energy change of a reaction is given by ΔG = ΔH - TΔS For a reaction to be spontaneous, ΔG should be -ve. If both ΔH and ΔS are positive ΔG can be -ve if TΔS>ΔH in magnitude. Thus, entropy ... is low, TΔS should be greater than ΔH (ii) If ΔS is small, T should be so large that TΔS>ΔH.
Description : Entropy change of the reaction, H2O (liquid) → H2O (gas), is termed as the enthalpy of (A) Solution (B) Vaporisation (C) Formation (D) Sublimation
Last Answer : (B) Vaporisation
Description : What American first proposed the free energy function G, which interrelates entropy and enthalpy?
Last Answer : ANSWER: J. WILLARD GIBBS
Description : Standard enthalpy of formation of ethane is -84.7kjper mol calculate the enthalpy change for the formation of 0.1kg ethane
Last Answer : Standard enthalpy of formation of ethane is -84.7kjper mol calculate the enthalpy change for the formation of 0.1kg ethane
Description : If the enthaply change for the transition of liquid water to steam is 30 KJ `"mol"^(-1)` at `27^(@)` C . The entropy change for the process would be
Last Answer : If the enthaply change for the transition of liquid water to steam is 30 KJ `"mol"^(-1)` at `27^(@)` C . The ... K^(-1)` D. `100 J mol^(-1)K^(-1)`
Description : For the reactions, (i) `H_(2)(g)+Cl_(2)(g)rarr 2HCl(g)+ xKJ` (ii) `H_(2)(g)+Cl_(2)(g)rarr 2HCl(l)+ yKJ` Which one of the following statement is correc
Last Answer : For the reactions, (i) `H_(2)(g)+Cl_(2)(g)rarr 2HCl(g)+ xKJ` (ii) `H_(2)(g)+Cl_(2)(g)rarr 2HCl(l)+ ... x gt y B. x lt y C. x = y D. More data required
Description : Assertion :- Entropy of system increases for a spontaneous reactions. Reason :- Enthalpy of reaction always decreases for spontaneous reaction.
Last Answer : Assertion :- Entropy of system increases for a spontaneous reactions. Reason :- Enthalpy of reaction ... D. If both Assertion & Reason are false.
Description : The first law of thermodynamics is based on which of the following principles? a. conservation of mass b. the enthalpy-entropy relationship c. action – reaction d. conservation of energy
Last Answer : conservation of energy
Description : What is the energy absorbed during chemical reaction under constant volume conditions? A. Entropy B. Ion exchange C. Enthalpy D. Enthalpy of reaction
Last Answer : Enthalpy
Description : In any chemical reaction, a quantity that decrease to a minimum is: w) free energy x) entropy y) temperature z) enthalpy
Last Answer : ANSWER: W -- FREE ENERGY
Description : Specific __________ does not change during phase change at constant temperature and pressure. (A) Entropy (B) Gibbs energy (C) Internal energy (D) Enthalpy
Last Answer : (B) Gibbs energy
Description : 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
Last Answer : Randomness or disorder
Description : The change that the system that undergoes from one equilibrium state to another is known as a. oath b. process c. enthalpy change d. entropy change
Last Answer : process
Description : 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
Last Answer : Some heat transfer occurs
Description : A state occurs in isentropic process a. The change in entropy is 0 b. The change in entropy is 1 c. The change in enthalpy is 0 d. The change in enthalpy is 1
Last Answer : The change in entropy is 0
Description : Regardless of the process, the change in enthalpy firm moles of ideal gas is a. Heat b. Enthalpy c. Entropy d. Density
Last Answer : Heat
Description : 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.
Last Answer : Answer : d
Description : 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.
Last Answer : Answer : a
Description : Change in enthalpy of a system is the heat supplied at (a) constant pressure (b) constant temperature (c) constant volume (d) constant entropy (e) N.T.P. condition.
Description : Given standard enthalpy of formation of `CO(-110 "KJ mol"^(-1))` and `CO_(2)(-394 "KJ mol"^(-1))`. The heat of combustion when one mole of graphite bu
Last Answer : Given standard enthalpy of formation of `CO(-110 "KJ mol"^(-1))` and `CO_(2)(-394 "KJ mol"^(-1))`. The heat ... B. `-284` KJ C. `-394` KJ D. `-504` KJ
Description : The enthalpy of combustion of `H_(2)` , cyclohexene `(C_(6)H_(10))` and cyclohexane `(C_(6)H_(12))` are `-241` , `-3800` and `-3920KJ` per mol respect
Last Answer : The enthalpy of combustion of `H_(2)` , cyclohexene `(C_(6)H_(10))` and cyclohexane `(C_(6)H_(12))` are `-241 ... "KJ mol"^(-1)` D. `242 "KJ mol^(-1)`
Description : Given that standard heat enthalpy of `CH_(4), C_(2)H_(4)` and `C_(3)H_(8)` are -17.9, 12.5, -24.8 Kcal/mol. The `Delta H` for `CH_(4)+C_(2)Hrarr C_(3)
Last Answer : Given that standard heat enthalpy of `CH_(4), C_(2)H_(4)` and `C_(3)H_(8)` are -17.9, 12.5, -24.8 Kcal ... . `-30.2` Kcal C. 55.2 Kcal D. `-19.4` Kcal
Description : Calculate the enthalpy of vaporisation per mole for ethanol. Given `DeltaS = 109.8 J K^(-1) mol^(-1)` and boiling point of ethanol is `78.5^(@)`.
Last Answer : Calculate the enthalpy of vaporisation per mole for ethanol. Given `DeltaS = 109.8 J K^(-1) mol^(-1)` ... KJ mol^(-1)` D. Some more data is required
Description : Ionization enthalpy of Li is 520 kJ mol^(-1) while that of F is 1681 kJ mol^(-1) . Explain.
Last Answer : Ionization enthalpy of Li is 520 kJ mol-1 while that of F is 1681 kJ mol-1. Explain.
Description : For the gas phase reaction `PCl_(5)rarrPCl_(3)(g)+Cl_(2)(g)` which of the following conditions are correct?
Last Answer : For the gas phase reaction `PCl_(5)rarrPCl_(3)(g)+Cl_(2)(g)` which of the following conditions are correct? A ... D. `Delta H gt 0` and `Delta S lt 0`
Description : At 473 K,`K_(c)` for the reaction `OCl_(5(g))rArrPCl_(3(g))Cl_(2(g))` is `8.3xx10^(-3)`. What will be the value of `K_(c)` for the formation of `PCl_(
Last Answer : At 473 K,`K_(c)` for the reaction `OCl_(5(g))rArrPCl_(3(g))Cl_(2(g))` is `8.3xx10^(-3)`. What will be ... 3)` B. 120.48 C. `8.3xx10^(-3)` D. 240 .8
Description : What is the standard enthalpy change at 298 K for the following reaction? `CO_(2) (g)+ C("diamond") rarr 2CO(g)` Given : `DeltaH_(f)^(@)(CO,g) = - 110
Last Answer : What is the standard enthalpy change at 298 K for the following reaction? `CO_(2) (g)+ C("diamond") rarr 2CO(g ... `+172.5 kJ//mol` D. `170.5 kJ//mol`
Description : The enthalpy change for the reaction `2C("graphite")+3H_(2)(g)rarrC_(2)H_(6)(g)` is called
Last Answer : The enthalpy change for the reaction `2C("graphite")+3H_(2)(g)rarrC_(2)H_(6)(g ... combustion C. Enthalpy of hydrogenation D. Enthalpy of vaporisation
Description : The enthalpy change `(Delta H)` for the reaction `N_(2) (g)+3H_(2)(g) rarr 2NH_(3)(g)` is `-92.38 kJ` at `298 K`. What is `Delta U` at `298 K`?
Last Answer : The enthalpy change `(Delta H)` for the reaction `N_(2) (g)+3H_(2)(g) rarr 2NH_(3)(g)` is `-92.38 kJ` at ` ... -87.42 kJ` C. `-97.34 kJ` D. `-89.9 kJ`