Question

Propane burns in oxygen to produce carbon dioxide and steam. Which of the chemical equations matches the reaction above?

A. C3H8 + 5O2 3CO2 + 4H2O


B. C3H8 + 4O2 2CO2 + 4H2O


C. C3H8 + 6O2 2CO2 + 8H2O


D. C3H8 + 6O2 3CO2 + 6H2O

Answer 1

A

Step-by-step explanation:

Propane burns in oxygen to produce carbon dioxide and steam. The chemical equation is written with chemical symbols below:

C3H8 + O2 CO2 + H2O

There are three carbon atoms on the left side, but only one on the right, so we need to put a 3 in front of the carbon dioxide molecule to give three carbons on each side:

C3H8 + O2 3CO2 + H2O

There are eight hydrogen atoms on the left side and two on the right side, so we need to place a 4 in front of the water molecules on the right side:

C3H8 + O2 3CO2 + 4H2O

There are 2 oxygen atoms on the left side and 10 on the right side, so we need to place a 5 in front of the oxygen molecule on the left side:

C3H8 + 5O2 3CO2 + 4H2O

The equation has been balanced.

Answer 2

Answer: A

Step-by-step explanation:

Balancing a chemical reaction, we must take into consideration every element both at the reactant and products side.

Since we were told propane reacts with oxygen to produce steam and carbon dioxide, we already have an idea of how the equation would be just remaining balancing the stoichiometry of the equation.

C3H8 + 5O2 =====》 3CO2 + 4H20

From the equation above,

3 atoms of carbon is present at reactant side and 3 carbon is also at the product side.

8 Hydrogen at reactant = 4 * 2 Hydrogen at product.

10 Oxygen at reactant = 3*2 + 4 oxygen at product

The equation must be balanced because law of conservation of matter must take place in every chemical reaction, matter can neither be created nor destroyed but can change form.