Question

On heating blue coloured powder of copper (II) nitrate in a boiling tube copper oxide (black), oxygen gas and a brown gas X is formed. Which type of reaction is this?
A. Displacement reaction
B. Precipitation reaction
C. Decomposition reaction
D. All the above

Answer 1

Hint: We know that a chemical reaction is understood as a method in which chemical reagents called reactants with different compositions react together to give new chemicals, called products. In a general reaction, \[{\rm{AB}} \to {\rm{A}} + {\rm{B}}\], the breaking of molecule AB results in the formation of one molecule of A and B each or in simple words, one reactants breaks to form two products.

Step by step answer:
Any chemical change is a chemical reaction that can be represented by a word equation in which full reactant and product names have been used. The other method of representation is chemical equations in which we use chemical formulae of all the involved species. There are different types of chemical reactions, which are combination reactions, decomposition reactions, displacement reactions, double displacement reactions and redox reactions.

According to the question when copper nitrate is heated in a boiling tube it dissociates into copper oxide oxygen and a brown gas. We can represent it by the equation.

\[{\rm{2Cu}}{\left( {{\rm{N}}{{\rm{O}}_{\rm{3}}}} \right)_{\rm{2}}}\left( {\rm{S}} \right) \to 2{\rm{CuO}}\left( {\rm{S}} \right) + {\rm{4N}}{{\rm{O}}_{\rm{2}}}\left( {\rm{g}} \right) + {{\rm{O}}_{\rm{2}}}\left( {\rm{g}} \right)\]

Copper nitrate is burned on a boil tube and it dissociates into their simpler part. This reaction requires some heat for completing their reaction. In this reaction, one single component is dissociating in their two or more parts, in the presence of heat this condition is satisfied in the decomposition reaction. This reaction is a type of thermal decomposition reaction, during the presence of heat.

Therefore, the correct answer is C.

There are three types of decomposition reaction,
1.Thermal decomposition reaction, in this reaction decomposition reaction occurs in the presence of heat. It can be known as an endothermic reaction.

2.Electrolytic decomposition reaction, this type of decomposition reaction is occurring in the presence of electric current. For example, when electric current is passed in the sodium chloride solution it dissociates into sodium ion and chlorine ion.

3.Photochemical decomposition reaction, this type of decomposition reaction occurs in the presence of sunlight.

Note: As we know that, the atoms of every reactant and product species are equal in a balanced chemical reaction. Decomposition reaction is used in many ways; it is used in the extraction of metals.