Question

A large volume of copper $\,(II)\,$ sulphate solution is left in an iron container overnight to identify the correct statement for the above reaction.
A.The solution evaporates completely and some copper $\,(II)\,$ sulphate crystals are left behind.
B.The part of the container in contact with the solution is coated with copper
C.Some fine iron particles are formed in the solution
D.Atmospheric oxygen reacts with copper $(II)\,$ sulphate to give black copper $\,(II)\,$ oxide.

Answer 1

Hint: Iron is put in the reactivity series above copper. In this order, elements placed above are more reactive than those placed underneath them. Iron is therefore more reactive than copper.

Complete step by step answer:
Let us first understand the type of reaction happening in the experiment mentioned in the question;
Copper ions are displaced by iron from an aqueous copper sulphate solution. Because, iron is more reactive than copper as per the reactivity series. This type of reaction involves the displacement of one metal by another more reactive metal and hence it is known as single displacement reaction.
In detail, a single replacement reaction, also referred to as a single displacement reaction, is a reaction in which another element in a complex is replaced by one element. Pure components are often the starting materials.
So, the chemical reaction in this question can be represented as;
$\,Fe(s) + CuS{O_4}(aq) \to FeS{O_4}(aq) + Cu(s)\,$

So, in this reaction as iron displaces copper, the container will be coated with copper. Hence, the answer to this question is option B.

Additional information: For certain forms of reactions, including single replacement reactions, the reactivity series, also called the activity series, lists elements in order of their reactivity. In the reactivity order, the more reactive elements will replace the less reactive elements, but not the other way around. For elements that form cations and elements that form anions, there are different rankings.

Note:
In fact, in a single displacement reaction, anion can be substituted by elements that form anions in a compound, and the cation can be substituted in a compound by elements that form cations. Usually metals will form cations.