What type of reaction is taking place in the cell above? What is the reading on the voltmeter? Switch S is now closed - NSC Technical Sciences - Question 6 - 2024 - Paper 2

The reading on the voltmeter indicates the potential difference between the two half-cells. The standard electrode potential can be calculated as:

$E_{cell} = E_{cathode} - E_{anode}$

Given that the potentials are $E_{cathode} = -0.13 V$ and $E_{anode} = -1.66 V$, we find:

$E_{cell} = -0.13 - (-1.66) = 1.53 V$

Thus, the reading on the voltmeter is 1.53 V.

The voltmeter reading has already been calculated in the previous step as 1.53 V.

The electrode that will experience a decrease in mass is Pb (Lead). This is because during the redox reaction, lead is oxidized and loses electrons, leading to a reduction in its mass.

The net ionic cell reaction can be expressed as:

$2Al^{3+}(aq) + 3Pb(s) \rightarrow 2Al(s) + 3Pb^{2+}(aq)$

This equation represents the oxidation of aluminum ions and the reduction of lead ions.