Oxidation Numbers in SeO3^2-

The video tutorial explains how to determine the oxidation number for each element in the selenite ion (SeO3^2-). It begins by recognizing the ion's charge and setting up an equation where the sum of oxidation numbers equals the ion's charge. Selenium's oxidation number is unknown and represented as 'x', while oxygen is consistently -2. The equation is solved to find selenium's oxidation number as +4. The video concludes by verifying the sum of oxidation numbers matches the ion's charge.

What does the 2- charge in the SeO3^2- ion indicate about the sum of oxidation numbers?

• The sum is negative.

• The sum is positive.

• The sum is zero.

• The sum equals -2.

What is the typical oxidation number assigned to oxygen in compounds?

• -2

• 0

• +1

• +2

If each oxygen in SeO3^2- has an oxidation number of -2, what is the total contribution of oxygen to the oxidation state?

• -6

• 0

• -4

• -2

How do you determine the oxidation number of selenium in SeO3^2-?

• By using the atomic number of selenium.

• By guessing based on periodic table position.

• By using the known oxidation number of oxygen and the overall charge.

• By assuming it is zero.

What is the oxidation number of selenium in the SeO3^2- ion?

• +6

• +4

• -2

• 0

What is the total oxidation number of all elements in the SeO3^2- ion?

• -6

• +2

• 0

• -2

What is the purpose of verifying the oxidation numbers at the end of the calculation?

• To confirm the molecular weight.

• To determine the color of the compound.

• To check if selenium is a metal.

• To ensure the sum matches the ion's charge.