Ncert Solutions Chemistry Class 12th

This is a Assertion and Reason Type  as classified in NCERT Exemplar

Ans: Correct Option: (i)

  (i) Molar conductivity of weak electrolytes increases on dilution. In addition to solution the degree of dissociation increases leading to an increase in the number of ions produced. Therefore,   Λm shows a sharp increase.

Therefore, the assertion is correct, the reason is correct and the reason is a correct explanation for assertion. 

(ii) Assertion is correct, the reason is correct and the reason is the correct explanation of assertion. Therefore, this option is incorrect

(iii)Assertion and true both are correct therefore this option is incorrect

(iv) Assertion is true and the reason is false therefore this option is incorrect

(v)Assertion is true therefore this option is incorrect.

This is a Assertion and Reason Type  as classified in NCERT Exemplar

Correct Option: (i)

Ans: (i) Conductivity is due to the movement of ions. The number of ions present per unit volume decides the conductivity. It decreases on dilution. The number of ions per unit volume decreases on dilution. So, the assertion is correct, the reason is correct and the reason is the correct explanation of the assertion. Therefore, this option is correct

(ii) Assertion is correct, the reason is correct and the reason is the correct explanation of assertion. Therefore, this option is incorrect

(iii) Assertion and true both are correct therefore this option is incorrect

(iv) Assertion is true and the reason is false therefore this option is incorrect

(v) Assertion is true therefore this option is incorrect.

This is a Assertion and Reason Type  as classified in NCERT Exemplar

Ans: Correct Option: (iii)

(i)A chemical reaction is spontaneous when the Gibbs free energy is negative. This is possible when E_cell is positive. E_cathode < E_{annode .}Therefore, the assertion is correct and the reason is incorrect and the reason is not a correct explanation of assertion. Therefore, this option is incorrect

(ii) E_cathode < E_annode  reaction is spontaneous when the Gibbs free energy is negative. This is possible when E_cell is positive. E_cathode < E_annode  . Therefore, the assertion is correct and the reason is incorrect. Therefore, this option is correct

(iv) Assertion is true and the reason is false therefore this option is incorrect

(v) Assertion is true therefore this option is incorrect.

This is a Assertion and Reason Type  as classified in NCERT Exemplar

Ans: Correct Option: (iii)

  (i)The electrode potential of Cu²⁺/Cu is negative. The electrode potential of 2H⁺/H² is 0.00V. Therefore, the assertion is correct and the reason is incorrect and the reason is not a correct explanation of assertion. Therefore, this option is incorrect

(ii) E $°$ Cu²⁺/Cu  is not negative so the reason is incorrect. Therefore, this option is incorrect

(iii) The electrode potential of Cu²⁺/Cu is negative. The electrode potential of 2H⁺/H² is 0.00V. Therefore, the assertion is correct and the reason is incorrect. Therefore, this option is correct

(iv) Assertion is true and the reason is false therefore this option is incorrect

(v)Assertion is true therefore this option is incorrect.

This is a Matching Type Question as classified in NCERT Exemplar

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

 The rate rule was discovered experimentally and can be used to predict the reaction rate and reactant concentrations.

The rate constant is the proportionality constant that describes the relationship between the molar concentration of the reactants and the rate of a chemical reaction.

The rate constant (k) of a reaction is proportional to its temperature, i.e., for a given reaction at a given temperature, the rate constant (k) is constant.

The order of a reaction is a quantity that has been empirically determined. As a result, the reaction rate is mostly determined by the slowest phase of the reaction. In the event of a complicated reaction, the stoichiometric coefficients of this rate-determining step match to the reaction order.

This is a Matching Type Questions as classified in NCERT Exemplar

Ans:   (i) F₂ is a non-metal which is the best oxidizing agent since the standard reduction potential of F₂ is 2.87V.

(ii)Liis a metal and the strongest reducing agent because the standard reduction potential of Li is −3.05V.

(iii)Au³⁺ is a metal ion which is an oxidizing agent as standard reduction potential of Au³⁺ is 1.40V.

(iv) Br⁻is an anion that can be oxidized by Au³⁺ as standard reduction potential of Au³⁺ is 1.40V which is more than that of Br⁻ which is E $\mathit{Q}$ _Br2/Br−0=1.09V.

(v)Auis an unreactive metal

(vi)Li⁺ is a metal ion having the least value of standard reduction potential of 3.05V. Hence it is the weakest oxidizing agent

(vii)F⁻is an anion that is the weakest reducing agent as it has less oxidation potential.

Hence, the answer is:

(i)-c; (ii)-a; (iii)-g; (iv)-e; (v)-d; (vi)-b; (vii)-f