Passage III

An electrochemical cell (Figure 1) is constructed with an anode, a strip of zinc (Zn) placed in a solution of zinc ions (Zn2+), and a cathode, a strip of copper (Cu) or silver (Ag) placed in a solution of copper ions (Cu2+) or silver ions (Ag1+) , respectively. The solutions are connected by a salt bridge (a tube filled with a solution containing nitrate ions). The anode and cathode are connected to a voltmeter. Tables 1 and 2 show how the mass (g) of the anode or cathode, concentrations (M) of the ionic solutions, and temperature (°C), affect the voltage difference(V) between Zn and either Cu or Ag.

15. Which of the following conclusions about the relationship between the components of the electrochemical cells and the voltage difference is supported by Table 1?

Answer and Explanation

Your Answer is

Correct Answer is C

Explanation

According to the two tables, it can be seen that voltage difference has nothing to do with mass of anode or mass of cathode, so first exclude A & B;

Because it is found by comparing Cell 8 and Cell 9 As the temperature increases, the voltage difference increases, so exclude D