Chemistry

A solution of CuSO(_4) was electrolyzed between pure copper electrodes and the following results…

(a) A solution of CuSO(_4) was electrolyzed between pure copper electrodes and the following results were obtained:

Mass of copper anode before experiment = 7.20 g

Mass of copper anode after experiment = 4.00 g

Mass of copper cathode before experiment = 5.75 g

From the information provided,

(i) calculate the mass of the cathode, after the experiment.

(ii) write an equation for the reaction at the I. anode, II. cathode.

(iii) state whether the colour of the solution would change during the electrolysis. Give a reason for your answer.

(iv) if the electrolysis was carried out for 1 hour 20 minutes with a current of 2.0 amperes, determine the value of the Faraday.

 

(b) Consider the reaction represented by the following equation:

MnO(^-_4) + I(^-) + H(^+)  (to) I(_2) + H(_2)O + Mn(^{2+}) 

Write balanced half equation for the (i) oxidation reaction, (ii) reduction reaction.

 

(c)(i) Describe briefly how tin can be extracted from its ore.

(ii) State one use of tin.

(iii) Mention one property that makes tin suitable for the use stated in (c)(ii)

 

(d)(i) What is meant by the term pollution?

(ii) Explain why it is dangerous to run a generator in a closed room.