Question

1. (a) fig. 8.1 shows three electric cells that were used to compare reactivity of three metals a, b and c. (i) explain why metals a, b and c are all more reactive than copper. (ii) arrange the metals a, b and c in order of decreasing reactivity (starting with the most reactive). (iii) explain the trend in (ii). (b) (i) state and explain the trend in the reactivity of group (vii) elements. trend explanation (ii) deduce with reason(s) the physical state of astatine at room temperature. state

Explanation:

(a)(i)

In an electrochemical cell, a potential difference is generated when a more reactive metal loses electrons more readily than a less - reactive one. Since there is a potential difference when metals A, B, and C are paired with copper, they are more reactive as they can displace copper from its salt solution in the acid medium by losing electrons more easily.

The greater the potential difference in an electrochemical cell, the greater the difference in reactivity between the two metals. Since the potential difference with metal A (2.6 V) is the highest, followed by metal C (0.80 V) and then metal B (0.15 V), the order of decreasing reactivity is based on these potential differences.

The potential difference in an electrochemical cell is related to the ease of oxidation of the metal. A higher potential difference means the metal loses electrons more readily and is more reactive. Metal A has the highest potential difference, so it loses electrons most easily among the three, followed by C and then B.

Answer:

A potential difference is produced when paired with copper, indicating they can displace copper and lose electrons more readily.

(a)(ii)