Hey there! We receieved your request
Stay Tuned as we are going to contact you within 1 Hour
One of our academic counsellors will contact you within 1 working day.
Click to Chat
1800-5470-145
+91 7353221155
Use Coupon: CART20 and get 20% off on all online Study Material
Complete Your Registration (Step 2 of 2 )
Sit and relax as our customer representative will contact you within 1 business day
OTP to be sent to Change
1. Exactly 0.200 mole electrons is passed through two electrolytic cells in series. One contains silver ion, and the other, zinc ion .assume that the only cathode reaction in each cell is the reduction of the ion to the metal. How many grams of each metal will be deposited? (at. Mass of zn = 65, ag = 108)
a. 108g ag and 65 g zn.
b. 108 ag and 32.5g zn.
c. 21.6 ag and 6.5 g zn.
d. 21.6 g ag and 13 g zn.
2. A steady current of 30.0A for 70.2 min corresponds to a passage of a. 1.2610^5 electrons.
b. 1.26×10^5 f.
c. 1.31 f.
d. 1.31 c.
3. Cu+ is not stable and undergoes disproportion. E for cu+ disproportionation.
(E° cu2+/cu =0.153V , E° cu+/cu=0.53V).
Hi
Ans 1:
For silver , the conversion is Ag+ + e- -> Ag
Therefore 1 mole of electrons are reqd to make 1 mole i.e 108 gm of silver. hence .2 moles of electron will make .2x108 = 21.6 gm of silver.
For zinc, the connversion is Zn2+ + 2e- -> Zn
Therefore 2 moles of elctrons are reqd to make 1 mole i.e 65 gm of zinc, hence .2 mole electrons shall make .2x65/2 = 6.5 gm of zinc.
Ans 2:
For a steady flow, the current I in amperes can be calculated with the following equation:
where
More generally, electric current can be represented as the time rate of change of charge, or
therefore, Q= 30 A x 70.2 x 60 sec = 126360 coulombs
1 faraday = 96 485.3415 coulombs
Therefore answer is 126360/96485.3415 = 1.31 faraday
Please repost the third question, the question is not clear.
1) for silver deposition : Ag+ + e- ------> Ag
1 mole 1 mole
so , 0.2 moles of Ag is deposited i.e., 0.2*108 = 21.6 grams
for zinc deposition : Zn2+ + 2e- ------> Zn
2 mole 1 mole
so , 0.1 moles of Zn is deposited i.e., 0.1*65 = 6.5 grams
So option is C
2) Electric current is the rate of charge flow past a given point in an electric circuit, measured in Coulombs/second which is named Amperes
so Q = i*t
Q=30*70.2*60
Q = 126360 Coulombs
but 1 faraday = 96485 Coulombs
So its Q = 1.31 faraday
3) I want to make a small correction to question reg. elecric potential of cu2+/cu+ ( taken frm standard books ) Its cu2+/cu+ =0.153V i.e., cu2+ + e- ------> cu+ E0 = 0.153 V Now going into problem: Cu+ solutions, tend to give a disproportion reaction: 2Cu+ ----- > Cu + Cu2+ cu+ + e- ------> cu E0 = 0.53 V so, nE0 = 0.53 V cu+ ------> cu2+ + e- E0 = - 0.153 V so, nE0 = - 0.153 V on adding above rxns we get 2Cu+ ----- > Cu + Cu2+ with E0 = +0.377 V
Get your questions answered by the expert for free
You will get reply from our expert in sometime.
We will notify you when Our expert answers your question. To View your Question
Win Gift vouchers upto Rs 500/-
Register Yourself for a FREE Demo Class by Top IITians & Medical Experts Today !