1
JEE Main 2023 (Online) 13th April Morning Shift
Numerical
+4
-1

$$\mathrm{A}_{2}+\mathrm{B}_{2} \rightarrow 2 \mathrm{AB} . \Delta H_{f}^{0}=-200 \mathrm{~kJ} \mathrm{~mol}^{-1}$$

$$\mathrm{AB}, \mathrm{A}_{2}$$ and $$\mathrm{B}_{2}$$ are diatomic molecules. If the bond enthalpies of $$\mathrm{A}_{2}, \mathrm{~B}_{2}$$ and $$\mathrm{AB}$$ are in the ratio $$1: 0.5: 1$$, then the bond enthalpy of $$\mathrm{A}_{2}$$ is ____________ $$\mathrm{kJ} ~\mathrm{mol}^{-1}$$ (Nearest integer)

2
JEE Main 2023 (Online) 12th April Morning Shift
Numerical
+4
-1

One mole of an ideal gas at $$350 \mathrm{~K}$$ is in a $$2.0 \mathrm{~L}$$ vessel of thermally conducting walls, which are in contact with the surroundings. It undergoes isothermal reversible expansion from 2.0 L to $$3.0 \mathrm{~L}$$ against a constant pressure of $$4 \mathrm{~atm}$$. The change in entropy of the surroundings ( $$\Delta \mathrm{S})$$ is ___________ $$\mathrm{J} \mathrm{K}^{-1}$$ (Nearest integer)

Given: $$\mathrm{R}=8.314 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}$$.

3
JEE Main 2023 (Online) 11th April Evening Shift
Numerical
+4
-1

The total number of intensive properties from the following is __________

Volume, Molar heat capacity, Molarity, $$\mathrm{E}^{\theta}$$ cell, Gibbs free energy change, Molar mass, Mole

4
JEE Main 2023 (Online) 11th April Morning Shift
Numerical
+4
-1

Solid fuel used in rocket is a mixture of $$\mathrm{Fe}_{2} \mathrm{O}_{3}$$ and $$\mathrm{Al}$$ (in ratio 1 : 2). The heat evolved $$(\mathrm{kJ})$$ per gram of the mixture is ____________. (Nearest integer)

Given: $$\Delta \mathrm{H}_{\mathrm{f}}^{\theta}\left(\mathrm{Al}_{2} \mathrm{O}_{3}\right)=-1700 \mathrm{~kJ} \mathrm{~mol}^{-1}$$

$$\Delta \mathrm{H}_{\mathrm{f}}^{\theta}\left(\mathrm{Fe}_{2} \mathrm{O}_{3}\right)=-840 \mathrm{~kJ} \mathrm{~mol}^{-1}$$

Molar mass of Fe, Al and O are 56, 27 and 16 g mol$$^{-1}$$ respectively.