Oxidation Numbers and Methane

The video tutorial explains how to determine the oxidation numbers in methane (CH4). It starts by noting that CH4 is a neutral molecule, meaning the sum of oxidation numbers is zero. Hydrogen, when bonded to a non-metal like carbon, has an oxidation number of +1. With four hydrogen atoms, the total positive charge is +4. To balance this, carbon must have an oxidation number of -4, resulting in a net charge of zero. The tutorial concludes with a summary of these calculations.

What is the overall charge of a methane (CH4) molecule?

• Positive

• Negative

• Neutral

• Depends on the environment

Why do the oxidation numbers in CH4 add up to zero?

• Because CH4 is a neutral molecule

• Because CH4 has a positive charge

• Because CH4 is an ion

• Because CH4 has a negative charge

What is the oxidation number of hydrogen when bonded to a non-metal?

• -1

• 0

• +1

• +2

How many hydrogen atoms are present in a methane molecule?

• Five

• Four

• Three

• Two

What is the oxidation number of carbon in methane (CH4)?

• +4

• -4

• 0

• +2

How does the oxidation number of carbon in CH4 balance the molecule?

• By being negative

• By being zero

• By being positive

• By being variable