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natka813 [3]
3 years ago
6

a) Calculate the mass of Li formed by electrolysis of molten LiCl by a current of 8.2 104 A flowing for a period of 14 hr. Assum

e the electrolytic cell is 70. percent efficient. (b) What is the energy requirement for this electrolysis per mole of Li formed if the applied emf is +8.4 V? answer in kWh/mol
Chemistry
1 answer:
Sonja [21]3 years ago
8 0

a) Answer:

= 210,000 gram or 210 Kg  

Explanation:

14 hr is equivalent to;

= 14 × 3600 s

But; 

8.2x10^4 A = 8.2x10^4 Coulomb /second = 8.2x10^4 C/s  

1 Faraday = 96485C  

Molar mass of Li: 6.941 g/mol  

Therefore;

{(8.2x10^4 C/s)×(14×3600s)×(6.941 g/mol)/(96485C/mol)}×70%  

= 2.1x10^5 gram  or 210 kg

b.  Answer;

= 0.23 kWh/mol

Explanation and solution;

Energy per mole is given by;

(96485C/mol) × (8.4V) = 8.10x10^5 (J/mol)  

= 8.10x10^5 (Ws/mol)  

Divide by 3600s/h to get:  

= 8.10x10^5 (Ws/mol)

= 225 Wh/mol

= 0.23 kWh/mol

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At equlibrium ;

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