Question

$Zn+{{H}_{2}}S{{O}_{4}}(dil)\to ZnS{{O}_{4}}+{{H}_{2}}\uparrow $
Above reaction is:
(a) Decomposition reaction
(b) Displacement reaction
(c) Combination reaction
(d) Synthesis reaction

Answer 1

Hint: In the above reaction, the zinc metal is being replaced with the hydrogen and the hydrogen is released in the form of the gas i.e. there is the displacement of the hydrogen. Now you can easily identify what type of reaction it is.

Complete step by step answer:
We will discuss the given options one by one;
(a) Decomposition reaction: First of all , let’s discuss what is a decomposition reaction. By the decomposition reaction, we mean the reaction in which the compound breaks down into two or more products. Example: consider the following general reaction as;
$AB\to A+B$
So, thus, the above given reaction is not a decomposition reaction and hence, this option is incorrect.
(b) Displacement reaction: By the displacement reaction, we means the reaction in which the one element or the atom is replaced by the other element in the same compound. Example: consider the following general reaction as;
$A+B-C\to A-C+B$
So, thus, the above given reaction is a displacement reaction because hydrogen is being replaced by the Zinc metal and hence, this option is correct.
(c) Combination reaction: By the combination reaction, we means the reaction in which two or more elements combine together to form a single compound. Example: consider the following general reaction as;
$X+Y\to XY$
So, thus, the above given reaction is not a combination reaction and hence, this option is incorrect.
(d) Synthesis reaction: By the synthesis reaction, we mean the reaction in which two or more different atoms or the elements come together to form a new different compound. Example: consider the following general reaction as;
$A+Y\to AY$
So, thus, the above given reaction is not a combination reaction and hence, this option is incorrect.
Hence, the above given reaction i.e. $Zn+{{H}_{2}}S{{O}_{4}}(dil)\to ZnS{{O}_{4}}+{{H}_{2}}\uparrow $ is a displacement reaction.

So, thus option (b) is correct.

Note: Whenever the metal is made to undergo reaction with the dilute sulphuric acid, it always results in the displacement of the hydrogen gas by the metal and the metal forms the salt and the hydrogen is released in the form of gas