Polyatomic Ions and Iron Compounds

Dr. B explains how to write the formula for Iron(III) Sulfate. The video covers identifying iron as a transition metal with a 3+ charge and recognizing sulfate as a polyatomic ion with a 2- charge. The crisscross method is used to balance these charges, resulting in the formula Fe2(SO4)3. The video concludes by verifying the charge balance to ensure the compound is neutral.

What is the charge of iron in Iron(III) Sulfate?

• 4+

• 1+

• 2+

• 3+

Which of the following is a polyatomic ion that needs to be memorized?

• Phosphate

• Sulfate

• Chloride

• Nitrate

What is the charge of the sulfate ion?

• 2-

• 3-

• 4-

• 1-

What method is used to balance the charges in Iron(III) Sulfate?

• Elimination

• Cross-multiply

• Crisscross

• Substitution

In the crisscross method, what is done with the charges?

• They are subtracted

• They are ignored

• They are swapped

• They are added

What is the correct formula for Iron(III) Sulfate?

• Fe(SO4)2

• Fe2(SO4)3

• FeSO4

• Fe3(SO4)2

How do the charges in Iron(III) Sulfate balance out?

• 3+ and 3-

• 2+ and 2-

• 6+ and 6-

• 4+ and 4-

Why is it important to verify the charges in a compound?

• To change its color

• To increase its weight

• To make it look good

• To ensure the compound is stable