Naming and Formulas of Polyatomic Ions

This video tutorial explains how to name the compound NH4Cr2O7 by identifying the ions involved: ammonium (NH4) and dichromate (Cr2O7). It discusses the importance of recognizing polyatomic ions and their charges, and how to balance these charges to correctly name the compound as ammonium dichromate. The tutorial emphasizes memorizing or referencing a table of polyatomic ions for accurate naming.

What is the chemical formula for ammonium dichromate?

• NH3)2Cr2O7

• NH4)2Cr2O7

• NH4)2CrO4

• NH3)2CrO4

Which ion is represented by NH4 in the compound?

• Dichromate ion

• Ammonium ion

• Chromate ion

• Nitrate ion

What is the name of the ion Cr2O7?

• Ammonium ion

• Dichromate ion

• Chromate ion

• Sulfate ion

When naming a compound with a polyatomic ion, what is typically written first?

• The metal

• The polyatomic ion

• The non-metal

• The anion

What is the charge of the dichromate ion in ammonium dichromate?

• 1-

• 1+

• 2+

• 2-

How many ammonium ions are needed to balance the charge of one dichromate ion?

• One

• Two

• Three

• Four