Oxidation Numbers and Barium Dichromate

This video tutorial explains how to determine the oxidation number of chromium in barium dichromate (BaCr2O7). It begins by identifying the compound as neutral, meaning the sum of oxidation numbers equals zero. The video assigns oxidation numbers to barium, chromium, and oxygen, and sets up an equation to solve for chromium's oxidation number. The solution reveals that each chromium atom has an oxidation number of +6. The video concludes by noting an alternative method using the dichromate ion's charge.

What is the overall charge of the compound barium dichromate?

• Positive

• Variable

• Negative

• Neutral

In which group of the periodic table is barium found?

• Group 1

• Group 3

• Group 4

• Group 2

What is the oxidation number of barium in barium dichromate?

• +3

• +4

• +2

• +1

What is the typical oxidation number of oxygen in compounds?

• -1

• -2

• -4

• -3

How many chromium atoms are present in barium dichromate?

• 3

• 2

• 1

• 4

What is the oxidation number of each chromium atom in barium dichromate?

• +7

• +5

• +4

• +6

What is the sum of the oxidation numbers in a neutral compound?

• 0

• +1

• -1

• +2

What is the ionic charge of the dichromate ion?

• -3

• -2

• -4

• -1

Which method was suggested as easier for finding the oxidation number of chromium?

• Using the periodic table

• Using the atomic mass

• Using the ionic charge of dichromate

• Using the neutrality of the compound