Chromium and Polyatomic Ions

The video tutorial explains how to write the formula for chromium-6 sulfate. It begins by identifying the element symbol for chromium and the polyatomic ion sulfate, which has a two-minus charge. The tutorial emphasizes the importance of balancing charges to achieve a neutral compound, requiring three sulfate ions to balance the six-plus charge of chromium. The final formula is presented as Cr(SO4)3.

What is the element symbol for chromium?

• Cr

• Cm

• Ch

• Co

Which of the following is a polyatomic ion?

• O2

• Na

• SO4

• Cl

What is the charge of the sulfate ion?

• 2+

• 3-

• 2-

• 1-

Why is it important to memorize common polyatomic ions in chemistry?

• They frequently appear in chemical compounds.

• They are often found on the periodic table.

• They have no charge.

• They are rarely used.

How many sulfate ions are needed to balance the charge of chromium-6 in chromium-6 sulfate?

• 3

• 2

• 1

• 4

What is the final formula for chromium-6 sulfate?

• Cr3(SO4)2

• Cr(SO4)3

• Cr2(SO4)3

• CrSO4