Question

# Chemical volcano is an example of:(A) Combination reaction (B) Decomposition reaction(C) Displacement reaction (D) None of the above

Hint: Chemical volcano is a reaction when ammonium dichromate decomposes; it gives off orange sparks and throws the green chromium oxide crystals into the air, producing an effect that looks like a miniature volcanic eruption.

Complete-step- by- step answer:
Reaction Equation for Chemical volcano:
${{(N{{H}_{4}})}_{2}}C{{r}_{2}}{{O}_{7}}\overset{Heat}{\mathop{\to }}\,C{{r}_{2}}{{O}_{3}}+4{{N}_{2}}\uparrow +4{{H}_{2}}O$

A decomposition reaction is a type of chemical reaction in which a single compound breaks down into two or more elements or new compounds. These reactions involve an energy source such as heat, light, or electricity that breaks the bonds of compounds.
According to the above definition of the decomposition reaction, the reaction equation of the chemical volcano is the best example of a decomposition reaction.

Hence option (B) decomposition reaction, is the correct answer.

1. Ammonium dichromate is an inorganic compound with the formula ${{(N{{H}_{4}})}_{2}}C{{r}_{2}}{{O}_{7}}$. In this compound, chromium is in +6 oxidation state, known as hexavalent chromium. It is a salt containing ammonium ions and dichromate ions.