Chemistry NCERT Exemplar Solutions Class 12th Chapter Three

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 ?

Given below are two statements: One is labeled as Assertion A and other is labeled as Reason R

Assertion A: Permanganate titrations are not performed in presence of hydrochloric acid.

Reason R: Chlorine is formed as a consequence of oxidation of hydrochloric acid.

In the light of the above statements, choose the correct answer from the option given below

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

The correct decreasing order for metallic character is

The ionic radii of ${\mathrm{O}}^{2-},{\mathrm{F}}^{-},{\mathrm{N}\mathrm{a}}^{+}$ and ${\mathrm{M}\mathrm{g}}^{2+}$ are in the order:

Element “E” belongs to the period 4 and group 16of the periodic table. The valence shell electron configuration of the element, which is just above “E” in the group is

Resistance of a conductivity cell (cell constant 129 m1) filled with 74.5 ppm solution of KCl is $100\Omega$ (labeled as solution 1). When the same cell is filled with KCl solution of 149 ppm, the resistance is $50\Omega$ (labeled as solution 2). The ratio of molar conductivity of solution 1 and solution 2 is i.e. $\frac{{\wedge }_1}{{\wedge }_2}=x*10^{-3}.$ The value of x is________. (Nearest integer)

The first ionization enthalpy on Na, Mg and Si, respectively, are : 496, 737 and 786 kJ mol^-1. The first ionization enthalpy (kJ mol^-1) of Al is:

$250\mathrm{m}\mathrm{L}$ of a waste solution obtained from the workshop of a goldsmith contains $0.1\mathrm{M}$ ${\mathrm{A}\mathrm{g}\mathrm{N}\mathrm{O}}_3$ and $0.1\mathrm{M}\mathrm{A}\mathrm{u}\mathrm{C}\mathrm{l}$ . The solution was electrolyzed at $2\mathrm{V}$ by passing a current of $1\mathrm{A}$ for 15 minutes. The metal/metals electrodeposited will be : $\left({\mathrm{E}}_{{\mathrm{A}\mathrm{g}}^{+}/\mathrm{A}\mathrm{g}}^{\mathrm{o}}=0.8\mathrm{V},{\mathrm{E}}_{{\mathrm{A}\mathrm{u}}^{+}/\mathrm{A}\mathrm{u}}^{\mathrm{o}}=1.69\mathrm{V}\right)$

$250\mathrm{m}\mathrm{L}$ of a waste solution obtained from the workshop of a goldsmith contains $0.1\mathrm{M}$ ${\mathrm{A}\mathrm{g}\mathrm{N}\mathrm{O}}_3$ and $0.1\mathrm{M}\mathrm{A}\mathrm{u}\mathrm{C}\mathrm{l}$ . The solution was electrolyzed at $2\mathrm{V}$ by passing a current of $1\mathrm{A}$ for 15 minutes. The metal/metals electrodeposited will be : $\left({\mathrm{E}}_{{\mathrm{A}\mathrm{g}}^{+}/\mathrm{A}\mathrm{g}}^{\mathrm{o}}=0.8\mathrm{V},{\mathrm{E}}_{{\mathrm{A}\mathrm{u}}^{+}/\mathrm{A}\mathrm{u}}^{\mathrm{o}}=1.69\mathrm{V}\right)$