Question

Magnesium carbonate, MgCO3, reacts with nitric acid, HNO3, to form magnesium nitrate and carbonic acid. Carbonic acid reacts to form water and carbon dioxide. Which type of reaction does carbonic acid undergo?
A. synthesis; carbonic acid forms from two smaller compounds
B. synthesis; carbonic acid forms from the elements
C. decomposition; carbonic acid breaks down into two simpler compounds
D. decomposition; carbonic acid breaks down into its elements

Answer 1

Answer: Option (C) is the correct answer.

Explanation:

When two different compounds combine to result in the formation of a new compound then this type of reaction is known as synthesis reaction.

On the other hand, when a compound decomposes to result in the formation of different compounds then it is known as decomposition reaction.

Therefore, the chemical equation for the given reaction is as follows.

       $MgCO_{3} + HNO_{3} \rightarrow MgNO_{3} + H_{2}CO_{3}$

       $H_{2}CO_{3} \rightarrow H_{2}O + CO_{2}$

Thus, we can see that carbonic acid dissociates to give water and carbon dioxide. Both water and carbon dioxide are compound.

Hence, we can conclude that it is a decomposition reaction; carbonic acid breaks down into two simpler compounds.

Answer 2

I believe the anser is C...