Q24 of 26 Page 1

Calculate e.m.f and ΔG for the following cell:


Given:


OR


(a) The conductivity of 0.1 mol L-1 solution of NaCl is 1.06×10-2Ω cm-1. Calculate its molar conductivity and degree of dissociation (α). Given λ°(Na+) = 50.1 S cm2 mol-1 and λ°(Cl-) = 76.5 S cm2 mol-1.


(b) What is the difference between primary battery and secondary battery? Give one example of each type.


For given reaction we identify the oxidation and reduction half-cell reactions





For the cell as Ag2+ has positive reduction it tends to udergo reduction. For the given cell representation,




The emf of a cell is given by,






The emf of cell is 1.0796 V


The Gibbs free energy is given by,




The Gibbs free energy is ΔG = 208.4 kJ


OR


(a)


Given:


k = 1.06×10-2 cm-1


C = 0.1 M


To find: molar conductivity and degree of dissociation


We know that,




Molar conductivity is 106


Molar conductivity


Degree of dissociation



Degree of dissociation = 0.837


(b)



More from this chapter

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22

Write the hybridization and shape of the following complexes:

(i) [Co(NH3)6]3+


(ii) [NiCl4]2-


 23

Seeing the growing cases of diabetes and depression among young children, Mr. Chopra, the principal of one of the reputed school organized a seminar in which he invited parents and principals. They all resolved this issue by strictly banning junk food in schools and introducing healthy snacks and drinks like soup, lassi, milk, etc. in school canteens. They also decided to make compulsory half an hour of daily physical activities for the students in the morning assembly. After six months, Mr. Chopra conducted the health survey in most of the schools and discovered a tremendous improvement in the health of the students.

After reading the above passage, answer the following questions:


(i) What are the values (at least two) displayed by Mr. Chopra?


(ii) As a student, how can you spread awareness about this issue?


(iii) Give two examples of artificial sweetners.


 25

(a) Account for the following:

(i) Ce4+ is a strong oxidizing agent in aqueous solution.


(ii) Transition metals have high enthalpy of atomization.


(iii) Mn shows maximum number of oxidation states in 3d series.


(b) Complete the following equations:


(i)


(ii)


26

(a) Write the structures of A, B, C, and D in the following reactions:


(b) Distinguish between the following:


(i)


(ii) Benzoic acid and phenol


OR


(a) Write the structures of the main products when ethanal reacts with the following reagents:


(i) HCN


(ii)


(iii) LiAlH4


(b) Arrange the following in the increasing order of their activity towards nucleophilic addition reaction:



(c) Give a sample chemical test to distinguish between the following pair of compounds: