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. decomposition; carbonic acid breaks down into its elements

B. synthesis; carbonic acid forms from the elements

C. decomposition; carbonic acid breaks down into two simpler compounds

D. synthesis; carbonic acid forms from two smaller compounds

Answer 1

MgCO3 + HNO3 -> MgNO3 + H2CO3
And then the H2CO3 -> H2O + CO2
(unbalanced)
So first it was a double replacement,
then it was a decomposition because the H2CO3 breaks down into H2O And CO2

Answer 2

Option C