How many seconds are required to produce 1.0 g of silver metal by the electrolys

Question

How many seconds are required to produce 1.0 g of silver metal by the electrolysis of a AgNO3 solution using a current of 60 amps?

a)5.4 × 10^4

b)3.2 × 10^3

C)15

D)3.7 × 10^-5

E)30

2)How many minutes will it take to plate out 16.22 g of Al metal from a solution of Al3+ using a current of 14.6 amps in an electrolytic cell?

53.0

66.2

153

199

1.42

1.26

0.94

0.78

1.10

e)11900

a)

53.0

b)

66.2

c)

153

d)

199

3)The standard cell potential (E°cell) for the reaction below is +1.10 V. The cell potential for this reaction is ________ V when the concentration of and

Zn (s) + Cu2+ (aq) Cu (s) + Zn2+ (aq)

1.42

1.26

0.94

0.78

1.10

e)11900

Explanation / Answer

Solution:- (1) In AgNO3, silver is present as Ag+ and so to get the silver metal reduction of Ag+ would be taking place and the equation could be written as...

Ag+(aq) + 1e- ----------> Ag(s)

From this equation 1 mol of electron deposits a mol of Ag and we know that 1 mol of electron carries one faraday that is 96485 C.

Let's convert 1.0 g of silver into moles and then moles of electrons.

1.0 g x (1mol Ag/107.87 g) x (1 mol of electron/1mol Ag) = 0.0093 mol of electrons

Now let's convert moles of electrons into Coblombs.

0.0093 mol of electrons x (96485 C/1mol of electron) = 897.31 C

we know that, Q = i.t

where Q is charge in Coulombs, i is current in ampere and t is time in seconds.

So far we have calculate Q and it is 897.31 C and i is given as 60 ampere. So, let's calculate t.

t = Q/i = 897.31/60 = 15 seconds.

So, the time required is 15 seconds and correct choice is (C).

(2) This one could also be solved same way we solved #1. The equation is little different since Al has +3 charge.

Al3+(aq) + 3e-    --------> Al(s)

1 mol of Al is deposited by 3 moles of electrons. Let's calculate Q for the given grams of Al.

16.22 g Al x (1mol Al / 27g Al) x (3 mol of electrons / 1 mol of Al) x (96485 C/ 1 mol of electron) = 173887.41 C

t = 173887.41/ 14.6 = 11910.10 seconds

Let's convert seconds into minutes..

11910.10 seconds x (1 minute/60 seconds) = 198.50 minutes = 199 minutes

So, the time required is 199 minutes and the correct choice is (d).

Related Questions

Navigate

• Browse (All)
• Browse H
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.