Propane burns in oxygen to produce carbon dioxide and water. what are the chemical formulas of the reactants and products?

For this question its the 3rd option

"The formulas of the reactants are C3H8 and O2. The formulas of the products are CO2 and H2O. "

Explanation:

This is followed by a second question:

What is the chemical equation for the burning of propane if all the products and reactants are in the gas phase?

The answer to this one is the 2nd option

"C3H8(g) + 5O2(g) → 3CO2(g) + 4H2O(g) "

I hope this helps! Have a good day!

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.

if you mean hydrogen and oxygen then water is the product