Use the standard electrode potentials given below to answer the questions that follow.

      

Use the standard electrode potentials given below to answer the questions that follow.



a) Select two half - cells which when combined will give the lowest e.m.f

b) Can a solution of silver nitrate be stored in a container of Zinc?

c) An iron jug was electroplated using Chromium. The chromium electrode and iron jug were thoroughly cleaned and weighed before being dipped into the electrolyte. Why was cleaning necessary?

d) A current of 0.75 Amperes was passed through the solution for one hour and four minutes. The mass of chromium deposited on the jug was 0.52g
(1Faraday = 96500C Cr = 52)

(i) Calculate the quantity of electricity passed.

(ii) How many moles in Chromium were deposited?

(iii) Calculate the quantity of electricity in coulombs required to deposit one mole of Chromium.

(iv) Deduce the charge of the Chromium ion.

  

Answers

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a) ii and iii

b) EMF = 0.80 – -0.76 = ±1.76 = +1.56v

- The reaction can occur hence cannot be stored

c) To remove any oxide layer.

d)i) Q = 0.75 x 64 x 60

= 2880C

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marto answered the question on September 17, 2019 at 08:02

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