1
JEE Main 2022 (Online) 25th June Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

At 25$$^\circ$$C and 1 atm pressure, the enthalpy of combustion of benzene (I) and acetylene (g) are $$-$$ 3268 kJ mol$$-$$1 and $$-$$1300 kJ mol$$-$$1, respectively. The change in enthalpy for the reaction 3 C2H2(g) $$\to$$ C6H6 (I), is :

A
+324 kJ mol$$-$$1
B
+632 kJ mol$$-$$1
C
$$-$$ 632 kJ mol$$-$$1
D
$$-$$ 732 kJ mol$$-$$1
2
JEE Main 2022 (Online) 24th June Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

At 25$$^\circ$$C and 1 atm pressure, the enthalpies of combustion are as given below :

Substance $${H_2}$$ C (graphite) $${C_2}{H_6}(g)$$
$${{{\Delta _c}{H^\Theta }} \over {kJ\,mo{l^{ - 1}}}}$$ $$ - 286.0$$ $$ - 394.0$$ $$ - 1560.0$$

The enthalpy of formation of ethane is

A
+54.0 kJ mol$$-$$1
B
$$-$$68.0 kJ mol$$-$$1
C
$$-$$86.0 kJ mol$$-$$1
D
+97.0 kJ mol$$-$$1
3
JEE Main 2021 (Online) 31st August Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language
The incorrect expression among the following is :
A
$${{\Delta {G_{System}}} \over {\Delta {S_{Total}}}} = - T$$ (at constant P)
B
$$K = {{\Delta H^\circ - T\Delta S^\circ } \over {RT}}$$
C
$$K = {e^{ - \Delta G^\circ /RT}}$$
D
For isothermal process $${w_{reversible}} = - nRT\ln {{{V_f}} \over {{V_i}}}$$
4
JEE Main 2021 (Online) 17th March Evening Shift
MCQ (Single Correct Answer)
+4
-1
During which of the following processes, does entropy decrease?

(A) Freezing of water to ice at 0$$^\circ$$C

(B) Freezing of water to ice at $$-$$10$$^\circ$$C

(C) N2(g) + 3H2(g) $$ \to $$ 2NH3(g)

(D) Adsorption of CO(g) on lead surface.

(E) Dissolution of NaCl in water

Choose the correct answer from the options given below :
A
(A), (C) and (E) only
B
(B) and (C) only
C
(A), (B), (C) and (D) only
D
(A) and (E) only
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