1
JEE Main 2017 (Online) 9th April Morning Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
A gas undergoes change from state A to state B. In this process, the heat absorbed and work done by the gas is 5 J and 8 J, respectively. Now gas is brought back to A by another process during which 3 J of heat is evolved. In this reverse process of B to A :
A
10 J of the work will be done by the gas.
B
6 J of the work will be done by the gas.
C
10 J of the work will be done by the surrounding on gas.
D
6 J of the work will be done by the surrounding on gas.
2
JEE Main 2017 (Online) 8th April Morning Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
For a reaction, A(g) $$ \to $$ A($$\ell $$); $$\Delta $$H= $$-$$ 3RT.
The correct statement for the reaction is :
A
$$\Delta $$H = $$\Delta $$U $$ \ne $$ O
B
$$\Delta $$H = $$\Delta $$U = O
C
$$\left| {} \right.$$$$\Delta $$H$$\left| {} \right.$$ < $$\left| {} \right.$$$$\Delta $$U$$\left| {} \right.$$
D
$$\left| {} \right.$$$$\Delta $$H$$\left| {} \right.$$ > $$\left| {} \right.$$$$\Delta $$U$$\left| {} \right.$$
3
JEE Main 2017 (Online) 8th April Morning Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
The enthalpy change on freezing of 1 mol of water at 5oC to ice at −5oC is :

(Given $$\Delta $$fusH = 6 kJ mol$$-$$1 at 0oC,
Cp(H2O, $$\ell $$ = 75.3J mol$$-$$1 K$$-$$1)
Cp(H2O s) =36.8 J mol$$-$$1 K$$-$$1)
A
5.44 kJ mol$$-$$1
B
5.81 kJ mol$$-$$1
C
6.56 kJ mol$$-$$1
D
6.00 kJ mol$$-$$1
4
JEE Main 2017 (Offline)
MCQ (Single Correct Answer)
+4
-1
Change Language
Given, $${C_{(graphite)}} + {O_2} \to C{O_2}(g)$$;

$${\Delta _r}{H^o}$$ = - 393.5 kJ mol-1

$${{\rm H}_2}(g)$$ + $${1 \over 2}{O_2}(g)$$$$\to {{\rm H}_2}{\rm O}(l)$$

$${\Delta _r}{H^o}$$ = - 285.8 kJ mol-1

$$C{O_2}(g)$$ + $$2{{\rm H}_2}{\rm O}(l) \to$$ $$C{H_4}(g)$$ + $$2{O_2}(g)$$

$${\Delta _r}{H^o}$$ = + 890.3 kJ mol-1

Based on the above thermochemical equations, the value of $${\Delta _r}{H^o}$$ at 298 K for the reaction

$${C_{(graphite)}}$$ + $$2{{\rm H}_2}(g) \to$$ $$C{H_4}(g)$$ will be :
A
+144.0 kJ mol–1
B
– 74.8 kJ mol–1
C
-144.0 kJ mol–1
D
+ 74.8 kJ mol–1
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