sec 3 ch4 l1 quiz 1

An electrochemical cell has the cell diagram: Mg_(s) / Mg²⁺_(aq) // Cu²⁺_(aq) / Cu_(s)

And the reduction potentials of its electrodes are:

·        Mg²⁺_(aq) + 2e^-           →           Mg_(s)                 E^o = -2.38 V

·        Cu²⁺_(aq) + 2e^-            →           Cu_(s)                  E^o = +0.34 V

Which of the following expresses the occurring reaction, as well as the electromotive force of this cell?

• a)     Spontaneous reaction / +2.72 V

• a)     Spontaneous reaction / +2.04 V

• a)     Nonspontaneous reaction / -2.72 V

• a)     Nonspontaneous reaction / -2.04 V

  The opposite figure shows the process of dipping two different metals in CuSO₄ solution.

What are the two metals (X) and (Y) which can give the highest volumeter reading?

• a)     Copper and magnesium.

• a)     Magnesium and platinum.

• a)     Magnesium and zinc.

• a)     Silver and platinum.

The opposite table shows the possibility of the reaction of 4 metals (R), (S), (T), and (U) with each other’s solutions.

What is the correct order of these metals in the electromotive series starting with most active?

• R → S → U → T

• R → T → U → S

• S → U → T → R

• U → R → T → S

 If E^o of the opposite half cell has a high negative value.

Which of the following is a correct conclusion?

• A is readily reduced.

•   A is readily oxidation.

• A⁺ is readily reduced

• A⁺ is readily oxidized.

According to the reduction potentials shown in the opposite table.

Which of the following statements is correct?

• AgNO₃ can be preserved in copper container.

• Mg(NO₃)₂ can be preserved in copper container.

• Cu(NO₃)₂ can be preserved in zinc container

• HgCl₂ can be preserved in copper container.

What happens when drops of I₂ are added to an aqueous solution contains Fe²⁺, Fe³⁺, and I^- ions?

• I₂ is reduced to I^-

• No oxidation-reduction reaction happens.

• I^- is oxidation to I₂

• Fe²⁺ is oxidized to Fe³⁺

On adding Fe to the aqueous solution of CuSO₄, copper precipitates … because …….

• Cu²⁺ is oxidized

• Cu²⁺ is reduced

• CuSO₄ is hydrolyzed

• CuSO₄ is ionized

Which of the following choices is not a cathodic reaction?

• Fe²⁺_(aq) → Fe³⁺_(aq) + e^-

• 2H⁺_(aq) + 2e^- → H_2(g)

• Ag⁺_(aq) → Ag(s) – e^-

• Cu²⁺_(aq) + 2e^- → Cu_(s)

Which of the following solutions becomes blue in colour when copper filings are added to it?

• AgNO₃

• Zn(NO₃)₂

•    Ba(NO₃)₂

• NaNO₃

On dipping a rod of metal (A) in a colorless concentrated aqueous solution of (B), the solution became blue in colour, and when NaCl_(aq) was added to the colorless solution, the precipitate (C) was formed which dissolves on adding a concentrated solution of ammonia to it …….

What is the choice which represents (A), (B), and (C)? 

• (A)Fe

  (B)Zn(No3)2

  (C)ZnCl2

• (A)Cu

  (B)AgNO3

  (C)AgCl

• (A)Ni

  (B)Al(NO3)3

  (C)AlCl3

• (A)Co

  (B)Pb(NO3)2

  (C)PbCl2