Unizor - Physics4Teens - Energy - Chemical Energy of Atomic Bonds
Channel: Zor Shekhtman on UNIZOR Education
Date: 2019-07-23

Unizor - Physics through a Looking Glass of Mathematician

Energy of Atomic Bonds
in Molecules

In this lecture we will analyze the energy aspect of chemical reactions.
Consider the reaction of burning of methane. This gas is used in regular gas stoves, so the reaction happens every time we cook something.
A molecule of methane consists of one atom of carbon C and four atoms of hydrogen H, the chemical formula of methane is CH4.
You can imagine a molecule of methane as a tetrahedron, in its center is an atom of carbon and on each of its four vertices is an atom of hydrogen.
A molecule of oxygen, as we know, consists of two atoms of oxygen and has a chemical formula O2.

As a result of the reaction of burning of methane, water and carbon dioxide are produced, according to the following equation:
CH4 + 2O2 = 2H2O + CO2
So, during this reaction
(a) four atomic bonds between carbon and hydrogen in one molecule of methane are broken,
(b) one atomic bond in each molecule of oxygen (out of two) are broken,
(c) two atomic bonds between hydrogen and oxygen in each molecule of water (out of two) are created,
(d) two atomic bonds between carbon and oxygen in a molecule of carbon dioxide are created.