Chemistry NCERT Exemplar Solutions Class 12th Chapter Twelve

If $75\mathrm{\%}$ of a first order reaction was completed in 90 minutes, $60\mathrm{\%}$ of the same reaction would be completed in approximately (in minutes)

(Take: $\mathrm{l}\mathrm{o}\mathrm{g}2=0.30;\mathrm{l}\mathrm{o}\mathrm{g}2.5=0.40$ )(Kinetics)

At $300\mathrm{K}$ , the vapour pressure of a solution containing 1 mole of $n$ -hexane and 3 moles of $\mathrm{n}$ -heptane is $550\mathrm{m}\mathrm{m}$ of $\mathrm{H}\mathrm{g}$ . At the same temperature, if one more mole of $\mathrm{n}$ -heptane is added to this solution, the vapour pressure of the solution increases by $10\mathrm{m}\mathrm{m}$ of $\mathrm{H}\mathrm{g}$ . What is the vapour pressure in $\mathrm{m}\mathrm{m}\mathrm{H}\mathrm{g}$ of $n$ -heptane in its pure state ?

The elements with atomic numbers 101 and 104 belong to, respectively:

Arrange the following in increasing order of reactivity towards nitration

A. p-xylene

B. bromobenzene

C. mesitylene

D. nitrobenzene

E. benzene                          

Choose the correct answer from the options given below

At $300\mathrm{K}$ , the vapour pressure of a solution containing 1 mole of $n$ -hexane and 3 moles of $\mathrm{n}$ -heptane is $550\mathrm{m}\mathrm{m}$ of $\mathrm{H}\mathrm{g}$ . At the same temperature, if one more mole of $\mathrm{n}$ -heptane is added to this solution, the vapour pressure of the solution increases by $10\mathrm{m}\mathrm{m}$ of $\mathrm{H}\mathrm{g}$ . What is the vapour pressure in $\mathrm{m}\mathrm{m}\mathrm{H}\mathrm{g}$ of $n$ -heptane in its pure state ?

On combustion of $\mathrm{L}\mathrm{i},\mathrm{N}\mathrm{a}$ and $\mathrm{K}$ in excess of air, the major oxides formed, respectively, are:

For one mole of an ideal gas, which of these statements must be true?

$\mathrm{U}$ and $\mathrm{H}$ each depends only on temperature

Compressibility factor $z$ is not equal to 1

${\mathrm{C}}_{\mathrm{P},\mathrm{m}}-{\mathrm{C}}_{\mathrm{v},\mathrm{m}}=\mathrm{R}$

$\mathrm{d}\mathrm{U}={\mathrm{C}}_{\mathrm{V}}\mathrm{d}\mathrm{T}$ for any process

Match the following:

Which of the following will react with ${\mathrm{C}\mathrm{H}\mathrm{C}\mathrm{l}}_3+$ alc. $\mathrm{K}\mathrm{O}\mathrm{H}$ ?

Identify the incorrect statement from the options below for the above cell: