Chemistry

 This is a Matching Type Question as classified in NCERT Exemplar

(i)- (b) ; (ii)- (c) ; (iii)- (a)

The rate of conversion in diamond is normally imperceptible.

Long-term rate at a moment's notice

The average rate is only for a short time.

This is a Matching Type Questions as classified in NCERT Exemplar

Ans:  (i)The reaction occurring at Lechlanche cells are 

At anode: Zn→Zn²⁺ + 2e⁻

At cathode: MnO₂ + NH₄⁺ + e⁻→MnO (OH)+NH₃

(ii)Ni−Cd is rechargeable. So it has a longer lifetime.

(iii) Energy in the fuel cell is due to the combustion process. It converts combustion energy into electrical energy 2H₂ + O₂→2H₂O

(iv) Mercury cells don't involve any solution and are used in hearing aids.

Hence, the answer is:

(i)-d; (ii)-c; (iii)-a, e; (iv)-b

This is a Matching Type Questions as classified in NCERT Exemplar

Ans:   (i)Conductivity k is defined as k = $°$

(ii)Molar conductivity is given by Λ_m = $*\mathit{T}$

(iii)Degree of dissociation  is given by $\frac{\mathbf{\Lambda }\mathbf{m}}{{\mathbf{\Lambda }}^0\mathbf{m}}$ ? = $\mathit{\alpha }$

(iv)Charge $\frac{\mathit{K}}{\mathit{C}}$  is the product of current and time $\mathit{}\mathit{Q}$  = I $\frac{\mathit{G}}{\mathit{R}}$

Hence, the answer is:

(i)-d; (ii)-c; (iii)-b; (iv)-a

This is a Matching Type Question as classified in NCERT Exemplar

(i)- (a) ; (ii)- (b) ; (iii)- (b); (iv)- (a)

 A zero-order reaction is one in which the reactant concentrations do not change over time and the rate of concentration remains constant.

A first-order reaction is one in which the rate of the reaction is linearly proportional to the concentration of only one ingredient. In other terms, a first-order reaction is a chemical reaction whose rate is determined by changes in only one of the reactants' concentration.

This is a Matching Type Questions as classified in NCERT Exemplar

Ans: (i) The cell reaction of a lead storage battery is as follows;

Pb + PbO₂ + 2H₂SO₄→2H₂SO₄ + 2H₂O

At cathode:PbO₂ (s)+SO₄²⁻ (aq)+2e⁻→2PbSO₄ (s) + 2H₂O (l)

At anode:Pb (s)+SO₄²⁻ (aq)→PbSO₄ (s)+2e⁻

Therefore Pb is the anode and PbO₂ is cathode

(ii)Mercury cell doesn't contain ions so it gives steady potential.

(iii)Fuel cells have maximum efficiency as they produce energy due to the combustion reaction of fuel.

(iv)Rusting is prevented by galvanization.

Hence, the answer is:

(i)-d ; (ii)-c ; (iii)-a ; (iv)-b

This is a Matching Type Questions as classified in NCERT Exemplar

Ans: (i)On dilution, the number of ions per unit volume increases so the molar conductivity increases with dilution.

(ii) E $°$ _cell is an intensive property as it is not dependent on the amount or mass of the substance. 

(iii) k is conductivity or be precise specific conductivity which depends on the number of ions

(iv) ΔrG_cell is an extensive property as it depends on the amount of substance or number of particles in the solution.

Hence, the answer is:

(i)-d ; (ii)a ; (iii)-b ; (iv)-c

This is a Matching Type Questions as classified in NCERT Exemplar

Ans: (i)The unit of  Λm is Scm²mol⁻¹

(ii) The unit of E_cell is m⁻¹

(iii) The unit of k is Scm⁻¹

(iv)The unit of  G∗ is m⁻¹

Hence, the answer is:

(i)-c ; (ii)-d ; (iii)-a ; (iv)-b

This is a Multiple Choice Questions as classified in NCERT Exemplar

Correct options: A and D

The pace of a reaction that is directly proportional to the concentration of the reacting substance is known as a first order reaction. 

Y=mn

k = $\frac{2.303}{\mathrm{t}}\mathrm{}$ log  $\frac{\mathbf{ }\mathbf{a}}{\mathbf{a}-\mathbf{x}\mathbf{ }}$

t = $\frac{2.303}{\mathrm{k}}\mathrm{}$ log $\frac{\mathbf{ }\mathbf{a}}{\mathbf{a}-\mathbf{x}\mathbf{ }}$

x= a- $\frac{\mathbf{a}}{2}$

x= $\frac{\mathbf{a}}{2}$

t $\raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$2$}\right.\mathbf{}$ _{= $\frac{2.303}{\mathrm{k}}\mathrm{}$} log $\frac{\mathbf{ }\mathbf{a}}{\mathbf{a}-\frac{\mathbf{a}}{2}\mathbf{ }}$   

$\frac{2.303}{\mathrm{k}}$ log2

= $\frac{0.693}{\mathrm{k}}$