Oxidation Numbers in Compounds

This video tutorial explains how to determine the oxidation numbers for each element in iron(III) phosphate (FePO4). It begins by discussing the concept of oxidation numbers in neutral compounds and ions, emphasizing that the sum of oxidation numbers in a neutral compound is zero. The video then focuses on the phosphate ion (PO4) and its charge, which is -3. Using this information, the tutorial calculates the oxidation numbers for iron, phosphorus, and oxygen in FePO4, concluding that iron is +3, phosphorus is +5, and oxygen is -2. The video ends with a brief conclusion and thanks from Dr. B.

What is the sum of oxidation numbers in a neutral compound?

• It is always positive.

• It is always negative.

• It is zero.

• It varies depending on the compound.

What is the charge of the phosphate ion (PO4) in FePO4?

• 2-

• 3-

• 1-

• 4-

Which element in FePO4 can have variable oxidation states?

• Iron

• Phosphorus

• Oxygen

• Hydrogen

What is the oxidation number of iron in FePO4?

• +3

• +2

• +5

• +4

How many oxygen atoms are present in the phosphate ion?

• Five

• Two

• Three

• Four

What is the oxidation number of oxygen in the phosphate ion?

• -3

• -2

• -1

• -4

If the oxidation number of phosphorus is represented as 'x', what equation represents the sum of oxidation numbers in PO4?

• x + 2(-2) = 0

• x + 4(-1) = 0

• x + 3(-2) = 0

• x + 4(-2) = 0

What is the oxidation number of phosphorus in the phosphate ion?

• +4

• +6

• +3

• +5

Which of the following is true about the oxidation numbers in FePO4?

• Iron is +2, Phosphorus is +4, Oxygen is -2

• Iron is +2, Phosphorus is +5, Oxygen is -2

• Iron is +3, Phosphorus is +4, Oxygen is -2

• Iron is +3, Phosphorus is +5, Oxygen is -2

What is the overall charge of the FePO4 compound?

• +2

• -1

• 0

• +1