Oxidation Numbers of Elements

The video tutorial explains the concept of oxidation numbers, starting with free elements like iron, which have an oxidation number of zero. It then explores how to determine the oxidation number of iron when it is bonded to other elements, such as in FeCl2 and FeCl3. The tutorial highlights that the oxidation number of iron can vary depending on its chemical environment, and it provides examples of calculating these numbers based on the known oxidation states of other elements like chlorine. The video concludes with a recap of the key points discussed.

What is the oxidation number of a free element like iron?

• Zero

• One

• Three

• Two

Why is the oxidation number of a free element zero?

• Because it has a positive charge

• Because it is in a compound

• Because there is no exchange of electrons

• Because it is bonded to other elements

In FeCl2, what is the oxidation number of chlorine?

• -1

• +2

• +1

• 0

How do you determine the oxidation number of iron in FeCl2?

• By knowing it is a free element

• By looking at the charge of the compound

• By assuming it is always +3

• By considering the oxidation number of chlorine

What is the oxidation number of iron in FeCl2?

• 0

• +3

• +2

• +1

In FeCl3, what is the total oxidation number of the chlorine atoms?

• -1

• 0

• -2

• -3

What is the oxidation number of iron in FeCl3?

• +1

• +2

• +3

• 0

Why do the oxidation numbers in FeCl3 add up to zero?

• Because iron has a negative charge

• Because chlorine has a positive charge

• Because it is a neutral compound

• Because it is an ion

What is the oxidation number of elements like Na or S8 in their natural state?

• -1

• 0

• +1

• +2

What is the oxidation number of H2O2 in its natural state?

• +1

• -1

• 0

• +2