Class 11th

This is a Short Answer Type Questions as classified in NCERT Exemplar

Ans: Conjugate acid and conjugate base can be shown as-

HCl(aq) + H₂O (l) ? H₃O⁺(aq) + Cl^-(aq) 

 acid        base        conjugate    conjugate

                             acid          base

This is a long answer type question as classified in NCERT Exemplar

It is lithium hydride (LiH) because it has significant covalent character due to the smallest alkali metal, LiH is very stable. It is almost nonreactive towards oxygen and chlorine. It reacts with Al2Cl2 to form lithium aluminium hydride.

8LiH+ Al₂Cl₆ → 2LiAlH₄ → LiCl

This is a long answer type question as classified in NCERT Exemplar

Since, a colourless liquid 'A' contains only hydrogen and oxygen and decomposes slowly on exposure to light but is stabilised by addition of urea, therefore, liquid A may be hydrogen peroxide. A is H₂O₂. 

Structure of H₂O₂ is given below.

This is a Long Answer Type Questions as classified in NCERT Exemplar

Ans: The equation can be written as-

A^p+_x  +  B^q- _y ? xA^p+ (aq) +  yB^q-

S moles of A and B dissolves to give x S moles of A^p+ and y S moles of Bq-.

K_sp = [A^p+]^x  [B^q-]^y = [x5]^x [y5]^y

= x^x y ^y 5 ^x+y

This is a long answer type question as classified in NCERT Exemplar

Mass of H₂O₂ = 68 g.

Mol. Mass of H₂O₂=34gmol^-1

∴1L of M solution of H₂O₂ will contain H₂O₂=34*5 g

∴2L of 5 M solution will contain H₂O₂=34*5*2=340g

or 200 mL of 5 solution will contain H₂O₂ = $\frac{340}{2000}$ $*$  200 = 34 g

Now 2H₂O₂ → 2H₂O+O₂

           64 g  32g

Now 68 g of H₂O₂ on decomposition will give O₂=32g

∴34g of H₂O₂ on decomposition will give O₂ = $\frac{34}{68}$ $*$    34 =16 g

(i) Industrial preparation: H₂O₂ is prepared by the auto-oxidation of 2- alkylanthraquinols

2-ethylanthraquinol ↔ H₂O₂⁺ oxidised product

2Fe₂+ (aq)+2H+ (aq)+H₂O₂ → Fe3 (aq)+2H₂O (l)

PbS (s)+4H₂O₂ (l) → PbSO4 (s)+4H₂O (l)

(ii) Reducing action of hydrogen peroxide 

2MnO₄^-+6H⁺+5H₂O₂→ 2Mn²⁺+8H₂O+5H₂

HOCl+H₂O₂ → H₃O⁺+Cl^-+O₂

Oxidising action of hydrogen peroxide 

2Fe²⁺+H₂O₂→ 2Fe³⁺+2OH^-

Mn²⁺+H₂O₂ → Mn⁴⁺+2OH^-

Acidic properties of H₂O₂

I₂+H₂O₂+2OH^-→ 2I^-+2H₂O+H₂

2MnO₄^-+3H₂O₂→ 2MnO₂+3O₂+2H₂O+2OH^-

This is a Long Answer Type Questions as classified in NCERT Exemplar

Ans: According to Le Chatelier's principle, when we raise the temperature, it shifts the equilibrium to left and decreases the equilibrium concentration of ammonia since it is an exothermic reaction. In other words, low temperature and high pressure is favourable for high yield of ammonia. There will be no change in equilibria on addition of argon (Ar).

This is a Long Answer Type Questions as classified in NCERT Exemplar

Ans: The values of K_c and Q_c are itself sufficient to explain the direction of reaction and less than or greater than one another decides the direction in which reaction will proceed as follows-

(i) As Qc < Kc, the reaction proceeds in the forward direction. 

(ii) If Qc > Kc, the reaction will proceed in the direction of reactants (reverse reaction). 

(iii) If Qc = Kc, no net reaction occurs.