1
JEE Main 2021 (Online) 17th March Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language
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
2
JEE Main 2020 (Online) 6th September Evening Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
For a reaction,
4M(s) + nO2(g) $$ \to $$ 2M2On(s)
the free energy change is plotted as a function of temperature. The temperature below which the oxide is stable could be inferred from the plot as the point at which :
A
the free energy change shows a change from negative to positive value
B
the slope changes from positive to negative
C
the slope changes from negative to positive
D
the slope changes from positive to zero
3
JEE Main 2020 (Online) 5th September Evening Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
Lattice enthalpy and enthalpy of solution of NaCl are 788 kJ mol–1, and 4 kJ mol–1, respectively.
The hydration enthalpy of NaCl is :
A
–780 kJ mol–1
B
–784 kJ mol–1
C
780 kJ mol–1
D
784 kJ mol–1
4
JEE Main 2020 (Online) 4th September Evening Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
Five moles of an ideal gas at 1 bar and 298 K is expanded into vacuum to double the volume. The work done is :
A
Zero
B
-RT $$\ln {{{V_2}} \over {{V_1}}}$$
C
CV (T2 – T1)
D
– RT (V2 – V1)
JEE Main Subjects
EXAM MAP