Cobalt(III) Nitrate and Polyatomic Ions

The video tutorial explains how to write the chemical formula for cobalt(III) nitrate. It begins by identifying the element symbol for cobalt and the charge indicated by the Roman numeral. The tutorial then describes the nitrate ion, its charge, and how to balance the charges to form a neutral compound. Finally, it demonstrates how to write the formula and name the compound based on the given formula.

What does the Roman numeral in cobalt(III) nitrate indicate?

• The atomic number of cobalt

• The charge of the cobalt ion

• The number of nitrate ions

• The number of electrons in cobalt

Which of the following is a characteristic of a polyatomic ion?

• It is always neutral

• It consists of a single atom

• It is found on the periodic table

• It has a charge that applies to the entire ion

What is the formula for the nitrate ion?

• N2O

• NH4

• NO3

• NO2

How do you achieve a net charge of zero in cobalt(III) nitrate?

• By using two nitrate ions

• By using three nitrate ions

• By using four nitrate ions

• By using one nitrate ion

Why are parentheses used in the formula for cobalt(III) nitrate?

• To denote a single nitrate ion

• To separate cobalt from nitrate

• To show the number of nitrate ions

• To indicate the charge of cobalt

What is the complete formula for cobalt(III) nitrate?

• Co(NO3)2

• Co(NO2)3

• Co(NO4)3

• Co(NO3)3

If given the formula Co(NO3)3, what is the charge on the cobalt ion?

• 1+

• 4+

• 2+

• 3+

What is the correct name for the compound with the formula Co(NO3)3?

• Cobalt(III) nitrite

• Cobalt(II) nitrate

• Cobalt(II) nitrite

• Cobalt(III) nitrate