Oxidation Numbers of Elements

The video tutorial explains how to determine oxidation numbers for elements like N2, O2, and Br2. It highlights a key rule that free elements have an oxidation number of zero, using examples such as sodium, iron, hydrogen gas, oxygen, and octa-sulfur. The importance of memorizing this rule is emphasized, along with a brief mention of other rules for finding oxidation numbers. The video concludes with a specific example of N2 having an oxidation number of zero.

What is the oxidation number of diatomic molecules like N2 and O2?

• Two

• Three

• One

• Zero

Which of the following elements is considered a free element with an oxidation number of zero?

• Carbon

• Nitrogen

• Sodium

• Chlorine

What is the oxidation number of octa-sulfur (S8)?

• Eight

• Four

• Zero

• Sixteen

Why is it important to memorize the rule about free elements having an oxidation number of zero?

• It is necessary for determining the state of matter.

• It is used to balance chemical equations.

• It is the only way to determine the oxidation number of free elements.

• It helps in calculating molecular weight.

Which of the following is NOT a free element with an oxidation number of zero?

• Water

• Oxygen

• Hydrogen gas

• Iron