Ionic Compounds and Their Properties

Mr. Layman introduces the concept of writing formulas for ternary ionic compounds, focusing on polyatomic ions. The video reviews monatomic ions and their charges, then explains polyatomic ions with examples like nitrate and sulfate. It covers methods for writing formulas for ternary compounds, such as the crisscross and lowest common multiple methods, and provides examples with iron nitrate and aluminum chromate.

What charge does a group 1 metal like sodium typically have when it forms an ion?

• -2

• +2

• -1

• +1

What is the oxidation number of fluorine when it gains an electron?

• +2

• -2

• -1

• +1

Which of the following is a polyatomic ion?

• Nitrate

• Chloride

• Sodium

• Phosphide

What is the charge of a sulfate ion?

• -2

• +2

• -1

• +1

Which element is typically found in polyatomic ions like permanganate and chromate?

• Zinc

• Copper

• Manganese

• Iron

How do you indicate the charge of a transition metal in a compound?

• By using a subscript

• By using Roman numerals

• By using a suffix

• By using a prefix

What method can be used to determine the number of ions needed in a compound?

• Subtraction method

• Division method

• Addition method

• Crisscross method

In the compound iron(III) nitrate, what is the charge of the iron ion?

• +2

• +4

• +3

• +1

How many nitrate ions are needed to balance one iron(III) ion?

• 2

• 4

• 1

• 3

What is the formula for aluminum chromate?

• AlCrO4

• Al2(CrO4)3

• Al3(CrO4)2

• Al(CrO4)2