1
JEE Main 2023 (Online) 1st February Evening Shift
Numerical
+4
-1

The molality of a $$10 \%(\mathrm{v} / \mathrm{v})$$ solution of di-bromine solution in $$\mathrm{CCl}_{4}$$ (carbon tetrachloride) is '$$x$$'. $$x=$$ ____________ $$\times 10^{-2} ~\mathrm{M}$$. (Nearest integer)

[Given : molar mass of $$\mathrm{Br}_{2}=160 \mathrm{~g} \mathrm{~mol}^{-1}$$

atomic mass of $$\mathrm{C}=12 \mathrm{~g} \mathrm{~mol}^{-1}$$

atomic mass of $$\mathrm{Cl}=35.5 \mathrm{~g} \mathrm{~mol}^{-1}$$

density of dibromine $$=3.2 \mathrm{~g} \mathrm{~cm}^{-3}$$

density of $$\mathrm{CCl}_{4}=1.6 \mathrm{~g} \mathrm{~cm}^{-3}$$]

2
JEE Main 2023 (Online) 1st February Morning Shift
Numerical
+4
-1

The density of $$3 \mathrm{M}$$ solution of $$\mathrm{NaCl}$$ is $$1.0 \mathrm{~g} \mathrm{~mL}^{-1}$$. Molality of the solution is ____________ $$\times 10^{-2} \mathrm{~m}$$. (Nearest integer).

Given: Molar mass of $$\mathrm{Na}$$ and $$\mathrm{Cl}$$ is $$23$$ and $$35.5 \mathrm{~g} \mathrm{~mol}^{-1}$$ respectively.

3
JEE Main 2023 (Online) 31st January Evening Shift
Numerical
+4
-1
Assume carbon burns according to the following equation :

$2 \mathrm{C}_{(\mathrm{s})}+\mathrm{O}_{2(\mathrm{~g})} \rightarrow 2 \mathrm{CO}(\mathrm{g})$

when $12 \mathrm{~g}$ carbon is burnt in $48 \mathrm{~g}$ of oxygen, the volume of carbon monoxide produced is ___________ $\times 10^{-1} \mathrm{~L}$ at STP [nearest integer]

[Given: Assume $\mathrm{CO}$ as ideal gas, Mass of $\mathrm{C}$ is $12 \mathrm{~g} \mathrm{~mol}^{-1}$, Mass of $\mathrm{O}$ is $16 \mathrm{~g} \mathrm{~mol}^{-1}$ and molar volume of an ideal gas at STP is $22.7 \mathrm{~L} \mathrm{~mol}^{-1}$ ]
4
JEE Main 2023 (Online) 31st January Evening Shift
Numerical
+4
-1
A sample of a metal oxide has formula $\mathrm{M}_{0.83} \mathrm{O}_{1.00}$. The metal $\mathrm{M}$ can exist in two oxidation states $+2$ and $+3$.

In the sample of $\mathrm{M}_{0.83} \mathrm{O}_{1.00}$, the percentage of metal ions existing in $+2$ oxidation state is __________ $\%$. (nearest integer)