Oxidation States and Arsenate Ion

This video tutorial explains how to determine the oxidation state for each element in the arsenate ion, AsO4 3-. It begins by noting that the sum of oxidation numbers must equal the ion's charge. The video then details the known oxidation state of oxygen and calculates the unknown oxidation state of arsenic, resulting in a positive five. The tutorial concludes by verifying the calculation and summarizing the oxidation numbers for the arsenate ion.

What is the charge of the arsenate ion?

• 1-

• 2-

• 4-

• 3-

Why must the sum of oxidation numbers in an ion equal the ion's charge?

• To ensure the ion is stable

• To balance the chemical equation

• To satisfy the conservation of charge

• To determine the molecular weight

What is the typical oxidation state of oxygen in compounds?

• -2

• +1

• -1

• +2

How many oxygen atoms are present in the arsenate ion?

• 4

• 3

• 2

• 5

What is the oxidation state of arsenic in the arsenate ion?

• +4

• +1

• +5

• +3

How do the oxidation states of arsenic and oxygen in the arsenate ion add up to the ion's charge?

• 4*(-2) + 4 = -3

• 4*(-1) + 5 = -3

• 4*(-2) + 5 = -3

• 4*(-2) + 3 = -3