FORM 4 CHEMISTRY

ONLINE TEST SERIES

ELECTROCHEMISTRY

1. Which statement is correct?

 
 
 
 

2. Ag(s) + NO3 (aq) + H+(aq) —– Ag+(aq) + NO(g) + H2O(l)

      When the oxidation-reduction equation above is balanced, what is the coefficient for H+ (aq)?

 
 
 
 

3. Aqueous solutions of AgNO3, Cu(NO3)2 and Cr(NO3)3 are electrolyzed using the same quantity of electricity. How do the number of moles of metal formed compare?

 
 
 
 

4. In which reaction does chromium undergo a change in oxidation number?

 
 
 
 

5. Which reaction does not involve either oxidation or reduction?

 
 
 
 

6. For a voltaic (or galvanic) cell using Ag,Ag+ (1.0 M) and Zn,Zn2+ (1.0 M) half-cells, which of the following statements is incorrect

 
 
 
 

7. What happens to the Cr3+(aq) ion when it is converted to CrO42- (aq)?

 
 
 
 

8. Consider the following reactions.

Cu2+(aq) + 2e− …….. Cu(s) Eï = +0.34 V

Mg2+(aq) + 2e− ……… Mg(s) Eï = −2.36 V

Zn2+(aq) + 2e− ……….. Zn(s)   Eï = −0.76 V

 

      Which statement is correct?

 
 
 
 

9. Consider the standard electrode potentials of the following reactions.

Cr3+(aq) + 3e →Cr(s)         −0.75 V

Cd2+(aq) + 2e → Cd(s)      −0.40 V

 

      What is the value of the cell potential (in V) for the following reaction?

2Cr(s) + 3Cd2+(aq) → 2Cr3+(aq) + 3Cd(s)

 
 
 
 

10. What mass (in grams) of nickel could be electroplated from a solution of nickel(II) chloride by a current of 0.25 amperes flowing for 10 hours? 

 
 
 
 

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