Question

Ethanol contains the elements carbon, hydrogen, and oxygen. When ethanol burns, it chemically reacts with oxygen gas. C2H6O + O2 ethanol oxygen gas What elements will be present in the substances that are created when ethanol burns?

Answer 1

Answer: carbon, hydrogen, and oxygen only

Explanation: When a chemical reaction occurs, the atoms in the original set of substances are rearranged to form a new set of substances. The number of atoms of each element does not change.

The elements carbon, hydrogen, and oxygen are the only elements present in the original substances, so the only elements in the final substances after the reaction will be carbon, hydrogen, and oxygen, as well. The number of atoms of each element must be the same before and after the reaction.

Answer 2

The elements that will be present after the burning of Ethanol are;

(i) Carbon

(ii) Oxygen

(iii) Hydrogen

Step-by-step explanation:

The balanced chemical equation for the burning of ethanol is as follow;

C₂H₅OH + 3 O₂ → 2 CO₂ + 3 H₂O

It can be observed in given balanced chemical equation that there three elements involved in this entire reaction. The elements that present in the reactant side are also found on the product side. It means that the elements have just rearranged going from reactant to product.

This means that this reaction is obeying Law of Conservation of Mass which states that mass can neither be created nor destroyed but it can be changed from one form to another hence, to keep the mass on both sides of the reaction balanced the same elements should be present on the product side too.