Question

The metal which can replace copper from its salt solution is :
a.) silver
b.) mercury
c.) zinc
d.) gold

Answer 1

Hint: The metal with higher reactivity can replace the metal with lower reactivity in the series. The answer to this question is the metal with atomic number 30. This metal is also used for galvanisation. It has a silvery blue appearance and belongs to transition metal complexes. It belongs to the 3rd period.

Complete step by step answer :
This question is from electrochemistry. We know that anywhere only the stronger one can replace the weaker one. Even here, the stronger means the metal with higher reactivity. So, the metal with higher reactivity can replace the metal with lower reactivity from its salt solution. Further, we know that silver and gold are regarded as noble metals and in chemistry, the noble means that has the least reactivity. The silver and gold are not so reactive in general if we compare the metals. In fact, the copper is more reactive than silver and gold. Thus, silver and gold can not replace copper from its salt solution. Even the mercury which is a liquid non-metal. It is also not more reactive than copper. So, even not the mercury could replace copper from its salt solution.
Zinc metal is more reactive than copper. So, it will replace copper from its salt solution.

Thus, the option c.) will be the correct answer.

Note: It must be noted that by certain experiments, the reactivity of metals have been found practically and even theoretically values have been calculated. The species which has more reactivity will actually react faster than the other. So, it can replace the less reacting species because less reacting species require more time for reaction.