Areaction in which a substance reacts with oxygen, emitting heat and forming oxygen-containing compounds is an example of a(n):

a) acid-base reaction.
b) combustion reaction.
c) precipitation reaction.
d) gas evolution reaction.

B) combustion reaction.

Explanation:

A) acid-base reaction: When an acid reacts with a base, to form metal salt and water, this type of reaction is Acid Base reaction.

Example:

B) combustion reaction: When a hydrocarbon reacts with oxygen to produce carbon dioxide and water, this type of reaction is combustion reaction.

C) precipitation reaction: a reaction in which aqueous solution of two compounds on mixing react to form an insoluble compound which separate out as a solid are called precipitation reactions.

D) gas evolution reaction: a reaction in which one of the product is formed as a gas.