Cobalt Compounds and Naming Rules

The video tutorial explains how to name the compound CO2(SO4)3. It begins by identifying CO as cobalt, a transition metal, and SO4 as the sulfate ion, a polyatomic ion. The tutorial then details how to determine the charge of cobalt in the compound, using the known charge of sulfate. The final name of the compound is determined to be cobalt(III) sulfate, with the Roman numeral indicating the charge of the cobalt ion.

What is the first step in naming the compound Co2(SO4)3?

• Identify the charge of the metal

• Recognize the polyatomic ion

• Write the name of the metal as it appears on the periodic table

• Determine the overall charge of the compound

What is the name of the polyatomic ion SO4?

• Sulfur

• Sulfate

• Sulfide

• Sulfite

Why is it necessary to determine the charge of cobalt in Co2(SO4)3?

• To find the molecular weight

• To identify the correct polyatomic ion

• To balance the equation

• Because cobalt is a transition metal

How many sulfate ions are present in Co2(SO4)3?

• 3

• 2

• 4

• 1

What is the total negative charge contributed by the sulfate ions in Co2(SO4)3?

• 2-

• 4-

• 6-

• 8-

What Roman numeral is used in the name of Co2(SO4)3 to indicate the charge of cobalt?

• I

• II

• III

• IV

What is the correct name for the compound Co2(SO4)3?

• Cobalt(II) sulfate

• Cobalt(III) sulfate

• Cobalt(IV) sulfate

• Cobalt sulfate

Why are Roman numerals used in the naming of transition metal compounds?

• To denote the type of bond

• To represent the molecular weight

• To show the charge of the metal

• To indicate the number of atoms