Oxidation Numbers and Dichromate Ion

The video tutorial explains how to determine the oxidation number of chromium in the dichromate ion (Cr2O7 2-). It starts by setting up an equation based on the known oxidation number of oxygen and the overall charge of the ion. The tutorial then demonstrates how to solve for the oxidation number of chromium, showing that each chromium atom has an oxidation number of +6. The process is explained step-by-step, including setting up an algebraic equation to verify the result.

What is the charge of the dichromate ion, Cr2O7 2-?

• +2

• -2

• -1

• 0

What is the oxidation number of oxygen in most compounds?

• -1

• 0

• -2

• +1

How many oxygen atoms are present in the dichromate ion?

• 7

• 8

• 6

• 5

What is the total oxidation number for the two chromium atoms in Cr2O7 2-?

• +12

• +6

• +14

• +16

How do you find the oxidation number of a single chromium atom in Cr2O7 2-?

• Add 2 to the total

• Divide the total by 2

• Multiply the total by 2

• Subtract 2 from the total

What is the oxidation number of each chromium atom in Cr2O7 2-?

• +3

• +4

• +6

• +5

Which equation can be used to verify the oxidation number of chromium in Cr2O7 2-?

• 2x - 14 = -2

• 2x + 14 = -2

• 2x - 14 = 2

• 2x + 14 = 2

What is the purpose of setting up an algebraic equation in this context?

• To calculate the molecular weight

• To verify the oxidation number calculation

• To find the charge of the ion

• To determine the number of oxygen atoms