Oxidation Numbers of Phosphorus Compounds

The video tutorial explains how to determine the oxidation numbers for each element in phosphorus pentahydride (PH5). It begins by noting that PH5 is a neutral compound, meaning the oxidation numbers must sum to zero. The tutorial highlights that hydrogen, when bonded with a non-metal like phosphorus, has an oxidation number of +1. Therefore, each phosphorus atom must have an oxidation number of -5 to balance the five hydrogen atoms. The video concludes by verifying the calculations, ensuring the sum of oxidation numbers equals zero.

What does the absence of a positive or negative sign after PH5 indicate?

• It has a negative charge.

• It is a neutral compound.

• It is an ionic compound.

• It has a positive charge.

When hydrogen is bonded with phosphorus, what is its oxidation number?

• +2

• -1

• 0

• +1

How is the oxidation number of phosphorus determined in PH5?

• By considering it as a metal.

• By using the atomic number of phosphorus.

• By balancing the total oxidation numbers to zero.

• By assuming it is always +3.

What is the total oxidation number of all hydrogen atoms in PH5?

• +1

• 0

• -5

• +5

What is the final step to ensure the oxidation numbers are correct?

• Verify if they add up to zero.

• Check if they add up to the atomic number.

• Ensure they are all positive.

• Confirm they are all negative.