Equilibrium

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: option (iv) 

Since in all the given reaction, the volume is to be kept constant and an inert gas argon is added which will do not take part in reaction. So, the equilibrium will remain unaffected in all the given cases.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: option (i) 

If the equation is multiplied by 2, the equilibrium constant for the new equation is the square of K it means we must do the square of 5 that is 25. Then and on reversing the reaction the value of the equilibrium constant is inversed means the value of K comes out to be 1/25= 0.04. 

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: option (ii)

 Greater the boiling point, lower will be the vapour pressure.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: Option(i)

The given reaction is :-

N₂ (g) + 3H₂ (g) ?2NH₃ (g)

A/C to vart Hoff's eqn,

$\frac{\mathrm{d}\mathrm{l}\mathrm{n}\mathrm{K}}{\mathrm{d}\mathrm{T}\mathrm{}}\mathrm{}$ = $\frac{?\mathrm{M}}{\mathrm{R}\mathrm{T}2}$

K is dependent on temperature. As temperature remains constant at equilibrium, so K will remain constant in the given conditions.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: Option(i)

When the reaction is half completed, [A] = [B].
Thus, [B][A]=1
?G⁰=−RTInK=−RTIn(1)=0

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: Option(iii)

The equation for weak acid and weak base is given as-

pH=7+ $\frac{1}{2}$  ?(pKa?−pKb?)

K_a=1.8*10^-5

pK_a=−log (1.8*10-5) =5−log1.8 =4.744

pK_b?=−log (1.8*10-5) =4.744

pH=7+ $\frac{1}{2}$  ?(pKa?−pK_b?) =7

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: option (i)

pH for weak acid is given by the following equation:

pH= $\frac{1}{2}$ [pK_a−logC]

= $\frac{1}{2}$ [−log (1.74*10⁻⁵)−log0.01]

=3.4

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: option (iv)

Aqueous ammonia will absorb chloride ions and thus the equilibria will shift in forward direction and solubility of silver chloride will increase.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: option (iii)

When 0.1 mol dm^-3 NH₄OH and 0.05 mol dm^-3 HCl react total amount of HCl reacts with NH₄OH to form NH₄Cl and some NH₄OH will be left unreacted. Thus, the resultant solution contains NH₄Cl and NH₄OH which will produce a buffer solution.

This is a Multiple Choice Questions as classified in NCERT Exemplar

Ans: option (iii)

 BF₃ is an electron deficient species that is why it is a Lewis acid. (all Lewis acid can accept a pair of electrons.