Question

Which equation represents a decomposition reaction?

(1) CaCO3(s) ==>CaO(s) + CO2(g)
(2) Cu(s) + 2AgNO3(aq) ==>2Ag(s) + Cu(NO3)2(aq)
(3) 2H2(g) + O2(g) ==>2H2O(l)
(4) KOH(aq) + HCl(aq) ==>KCl(aq) + H2O(l)

Answer 1

Answer (1 )

CaCO3(s) ==>CaO(s) + CO2(g)

hope this helps!.

Answer 2

Answer : The correct option is, (1)

Explanation :

The option (1) reaction is an example of decomposition reaction because in this reaction the larger compound, calcium carbonate decomposes into smaller molecule, calcium oxide and carbon dioxide.

Decomposition reaction : It is a type of reaction in which a larger compound decomposes into a smaller molecule or elements.

`AB\rightarrow A+B`

The option (2) reaction is an example of single displacement reaction because in this reaction the most reactive metal, copper displace the less reaction metal, silver.

The option (3) reaction is an example of combination reaction because in this reaction two reactants, hydrogen and oxygen react to give a single product as water.

The option (4) reaction is an example of double displacement reaction because in this reaction a positive cation and a negative anion of two reactants exchange their places to give two new products.

Hence, the correct option is, (1)