Oxidation Numbers of Free Elements

The video explains the concept of oxidation numbers, focusing on free elements like Cl2, Na, Fe, O2, and S8. It highlights that the oxidation number for free elements is always zero, which is a crucial rule to remember. The video also mentions other rules for determining oxidation numbers in different compounds but emphasizes the zero oxidation number for free elements. Dr. B concludes the video by reiterating the importance of this rule.

Which of the following is an example of a free element?

• CO2

• NaCl

• Cl2

• H2O

What is the oxidation number of a free element like Cl2?

• 1

• -1

• 2

• 0

Why is it important to remember the oxidation number of free elements?

• It determines the color of the element.

• It helps in balancing chemical equations.

• It affects the melting point of the element.

• It is used to calculate molecular weight.

Which of the following statements is true about free elements?

• They have varying oxidation numbers depending on the compound.

• Their oxidation number is always zero.

• Their oxidation number is always negative.

• They always have a positive oxidation number.

What is reiterated about free elements in the conclusion?

• They have a positive oxidation number.

• Their oxidation number is zero.

• They are always found in compounds.

• Their oxidation number is negative.