1
JEE Main 2021 (Online) 25th February Morning Shift
Numerical
+4
-1
The reaction of cyanamide, NH2CN(s) with oxygen was run in a bomb calorimeter and $$\Delta$$U was found to be $$-$$742.24 kJ mol$$-$$1. The magnitude of $$\Delta$$H298 for the reaction

$$N{H_2}C{H_{(S)}} + {3 \over 2}{O_{2(g)}} \to {N_{2(g)}} + {O_{2(g)}} + {H_2}{O_{(I)}}$$

is _________ kJ. (Rounded off to the nearest integer) [Assume ideal gases and R = 8.314 J mol$$-$$1 K$$-$$1]
2
JEE Main 2021 (Online) 25th February Morning Shift
Numerical
+4
-1
The ionization enthalpy of Na+ formation from Na(g) is 495.8 kJ mol$$-$$1, while the electron gain enthalpy of Br is $$-$$325.0 kJ mol$$-$$1. Given the lattice enthalpy of NaBr is $$-$$728.4 kJ mol$$-$$1. The energy for the formation of NaBr ionic solid is ($$-$$) ____________ $$\times$$ 10$$-$$1 kJ mol$$-$$1.
3
JEE Main 2021 (Online) 24th February Evening Shift
Numerical
+4
-1
Assuming ideal behaviour, the magnitude of log K for the following reaction at 25$$^\circ$$C is x $$\times$$ 10$$-$$1. The value of x is ______________. (Integer answer)

$$3HC \equiv C{H_{(g)}} \rightleftharpoons {C_6}{H_{6(l)}}$$

[Given : $${\Delta _f}{G^o}(HC \equiv CH) = - 2.04 \times {10^5}$$ J mol$$-$$1 ; $${\Delta _f}{G^o}({C_6}{H_6}) = - 1.24 \times {10^5}$$ J mol$$-$$1 ; R = 8.314 J K-1 mol$$-$$1]
4
JEE Main 2020 (Online) 5th September Evening Slot
Numerical
+4
-0
For a dimerization reaction,
2A(g) $$\to$$ A2(g)
at 298 K, $$\Delta$$Uo = –20 kJ mol–1, $$\Delta$$So = –30 JK–1 mol–1,
then the $$\Delta$$Go will be _____ J.