## Question

Q ONE LITRE MIXTURE OF CO &CO2 IS PASSED THRU RED HOT CHARCOAL IN A TUBE THE NEW VOL . BECOMES 1.2L WHAT % OF CO IN MIXTURE INITIALLY?

Q AN Aq SOLn CONTAINING 100 g OF DISSOLVED MgSO4 IS FED TO A CRYSTALLIZER WHERE 80% SALT CRY. OUT AS MgSO4.6H2O CRYSTAL HOW MANY gm OF HEXAHYDRATE SALT CRY. ARE OBTAINED FROM CRYSTALLIZER=?

ELECTROCHEM

Fe3+  +  e- -----> Fe2+ = 0.77V

Fe --------.>  Fe3+  + 3e-     E = +0.04V

WHAT IS VALUE OF E* for Fe2+  +2e--------> Fe ?

Joshi sir comment

CO2 + C (charcoal) ------->  2CO

let us consider that initially volume of CO2 is x litre and that of  CO is (1-x) litre

so after the above written process net CO in final = 2x+1-x = 1.2      given

on solving x = 0.2 and 1-x = 0.8   now calculate %

MgSO4  -------------->   MgSO4 .6H2O

it means 120 gm (mw of compound) gives 228 gm MgSO4 . 6H2

so 80 gm will give 228*80/120     solve it

here 80 is used for 80% of 100 gm.

Fe+++  +  e-  ----->  Fe++                  E=  +0.77 V

Fe                ----->  Fe+++  + 3e-       E = +0.04 V