# True or false? Decomposition does not involve the production of a new substance.

Jul 21, 2016

Sure it does - it's true. In order for this to be false:

"Decomposition does not involve the production of a new substance."

...all decomposition reactions would have to produce nothing new. If I find just one counterexample, then it's false.

Decomposition of a substance is its breaking down into other different elements or compounds.

A fun example is carbonic acid (${\text{H"_2"CO}}_{3}$) decomposing in water ($\text{H"_2"O}$) to form liquid water and gaseous carbon dioxide (${\text{CO}}_{2} \left(g\right)$).

In other words, the fizz you get in soda is:

${\text{H"_2"CO"_3(aq) rightleftharpoons "H"_2"O"(l) + "CO}}_{2} \left(g\right)$

Simply from the molecular formulas, carbonic acid is an entirely different compound from water and carbon dioxide.

The only similarity is that the same atoms constitute the reactant as they do the products:

Reactant

• ${\text{H"_2"CO}}_{3} :$ $2 \times \text{H", 1xx"C", 3xx"O}$

Products

• $\text{H"_2"O} :$ $2 \times \text{H", 1xx"O}$
• ${\text{CO}}_{2} :$ $1 \times \text{C", 2xx"O}$

But since these are bonded differently, they couldn't be the same old substance that started the reaction. Therefore, they are new substances.