1000 questions Electrochemistry

Question 1

Write balanced overall ionic equations:

i) The addition of metallic Al to a Cu(NO₃)₂ solution.

ii) When metallic Cu is added to dilute HNO₃.

iii) When SO₂ is added to acidified solution of Cr₂O₇^2-.

iv) When H₂S is added to Fe(NO₃)₃ solution. (a pale yellow ppt is formed)

Question 2

In the reaction between iron and copper ions, the iron electrode has a specific charge. This charge changes when instead of having a copper electrode and copper ions, these are changed to zinc electrode and zinc ions. Explain.

Question 3

i) Use data from the table above to deduce the halide ion that is the weakest reducing
agent.

ii) Use data from the table to justify why sulfate ions should not be capable of
oxidising bromide ions.

iii) Use data from the table to calculate a value for the EMF of a hydrogen–oxygen fuel cell operating under alkaline conditions.

Question 4

Using electrochemical data from question 5 are the following reactions spontaneous?

i) $2F^-+2H^+\rightarrow F_2+H_2$

ii) $SO_2+4H_2O+O_2\rightarrow 4OH^-+SO_4^2^-$

iii) $2H_2O+Br_2\rightarrow O_2+4H^++2Br^-$

Question 5

Using electrochemical data from question 5 write the cell notations for the following reactions:

i) anode: I^– cathode: Br₂

ii) anode: OH^– cathode: O₂

iii) anode: SO₂ cathode: Cl₂

Question 6

Using the Nernst Equation, find the E_cell when the pH is 13, [Cl^–] is 4.3 mol dm^-3.

Nernst equation: $E_{cell}=E^0-\frac{0.059}{z}.log\frac{[products]}{[reactants]}$

Reaction is: OH^– + Cl₂