InterviewSolution
Saved Bookmarks
InterviewSolution
| 1. |
In the electrolysis of a `40L CuSO_(4)` solution, there are two possible reactions at anode `:` `i. Cu rarr Cu^(2+)+2e^(-)` `ii. 2H_(2)O rarr 4H^(o+)+4e^(-)+O_(2)` A current of `1.07 A ` is passed for 2 hours. The loss in the mass of `Cu` at anode was `1.27 g`. `(` Atomic weight of `Cu =63.5g mol ^(1))`. Which of the following statement`(s)` is `//` are correct ?A. `0.08 mol` of electrons are passed through the solution during entire electrolysisB. `224mL` of `O_(2)(g)` is liberated at `STP` at anode.C. Fraction of current in the production of `Cu^(2+)` ions `=0.5.`D. `pH` drops to 3 |
|
Answer» Correct Answer - a,b,c,d `a.` Statement `(a)` is correct Amound of `Cu` converted to `Cu^(2+)` ions `=(1.27g)/(63.5g mol^(-1))` `[2F-=1 mol `of `Cu^(2+)]` Amount of electrons involved `=2xx0.02=0.04 mol`. Amount of electrons actually passed through solution `=(1.07xx2xx60xx60)/(96500)` `0.08 mol` `b.` Statement `(b)` is correct Amount of electrons involved is converting `H_(2)O` to `O_(2)` `=0.08-0.04` `=0.04 mol` Amount of `O_(2)` liberated at anode `=(1)/(4)xx0.04` `=0.01mol` `:.` Volume of `O_(2)` produced at `STP` at anode `=0.01xx22400mL=224 mL` `c.` Statement `(c)` is correct Fraction of current used in the production of `Cu^(2+)` ions `=(0.04)/(.08)=0.5` `d.` Statement `(d)` is correct `:` `:gt `Mol of `H^(o+)` ions produced at andoe `=0.04 mol` `:. [H^(o+)]_(anode)=(0.04 mol)/(40L)=10^(-3)mol L^(-1)` `:. pH=-log(10^(-3))=3` |
|