NTA JEE Mains 1st feb 2023 Shift 2

The molality of a $$10\%(v/V)$$ solution of di-bromine solution in $$CCl_4$$ (carbon tetrachloride) is '$$x$$'. $$x =$$ ______ $$\times 10^{-2}$$ M. (Nearest integer)
[Given : molar mass of $$Br_2 = 160 \text{ g mol}^{-1}$$, atomic mass of $$C = 12 \text{ g mol}^{-1}$$, atomic mass of $$Cl = 35.5 \text{ g mol}^{-1}$$, density of dibromine $$= 3.2 \text{ g cm}^{-3}$$, density of $$CCl_4 = 1.6 \text{ g cm}^{-3}$$]

Which one of the following sets of ions represents a collection of isoelectronic species?
(Given : Atomic Number : F : 9, Cl : 17, Na = 11, Mg = 12, Al = 13, K = 19, Ca = 20, Sc = 21)

For electron gain enthalpies of the elements denoted as $$\Delta_{eg}H$$, the incorrect option is :

0.3 g of ethane undergoes combustion at $$27°C$$ in a bomb calorimeter. The temperature of calorimeter system (including the water) is found to rise by $$0.5°C$$. The heat evolved during combustion of ethane at constant pressure is ______ $$\text{kJmol}^{-1}$$.
(Nearest integer)
[Given : The heat capacity of the calorimeter system is $$20 \text{ kJ K}^{-1}$$, $$R = 8.3 \text{ JK}^{-1} \text{ mol}^{-1}$$. Atomic mass of C and H are 12 and 1 $$\text{g mol}^{-1}$$ respectively]

The effect of addition of helium gas to the following reaction in equilibrium state at constant volume, is :
$$PCl_5(g) \rightleftharpoons PCl_3(g) + Cl_2(g)$$

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : An aqueous solution of KOH when for volumetric analysis, its concentration should be checked before the use.
Reason (R) : On aging, KOH solution absorbs atmospheric $$CO_2$$.
In the light of the above statements, choose the correct answer from the options given below.

O − O bond length in $$H_2O_2$$ is $$\underline{X}$$ than the O − O bond length in $$F_2O_2$$. The O − H bond length in $$H_2O_2$$ is $$\underline{Y}$$ than that of the O − F bond in $$F_2O_2$$. Choose the correct option for $$\underline{X}$$ and $$\underline{Y}$$ from the given below.

The starting material for convenient preparation of deuterated hydrogen peroxide $$(D_2O_2)$$ in laboratory is:

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): Gypsum is used for making fireproof wall boards.
Reason (R): Gypsum is unstable at high temperatures.
In the light of the above statements, choose the correct answer from the options given below:

The correct order of bond enthalpy ($$\text{kJ mol}^{-1}$$) is: