Unit 7 - Naming and Formulas

What type of compound is NaCl?

• Ionic compound
• Covalent compound
• Binary acid
• Polyatomic compound
• Organic compound

Answer explanation

NaCl is a metal + nonmetal, so it's ionic.

Which of the following is a binary ionic compound?

• HNO₃
• CO₂
• MgBr₂
• NH₄OH
• Na₂SO₄

Answer explanation

Binary ionic = metal + nonmetal only. MgBr₂ fits.

Select all that are ionic compounds.

• NaCl
• NH₄NO₃
• SO₂
• K₂CO₃
• FeBr₃

Answer explanation

Ionic compounds involve metals or polyatomic ions. SO₂ is covalent.

Identify the correct name for CaCl₂.

• calcium dichloride
• calcium chloride
• calcium(I) chloride
• calcium chlorate
• calcium(II) chloride

Answer explanation

Ca has a fixed +2 charge. No Roman numeral or prefix needed.

Identify the correct name for FeBr₃.

• iron tribromide
• iron(III) bromide
• iron(I) bromide
• iron(II) bromide
• iron bromide

Answer explanation

Br = –1 × 3 = –3 → Fe must be +3.

Write the formula for aluminum iodide.

Answer explanation

Al = +3, I = –1 → Crisscross to get AlI₃.

Which of the following is not a rule for binary ionic naming?

• Metal first
• No prefixes
• Roman numerals if needed
• Charges in name
• “-ide” on nonmetal

Answer explanation

We never write charges in name (e.g., “iron +3” is incorrect).

Zn(NO₃)₂ is correctly named:

• zinc dinitrate
• zinc(II) nitrate
• zinc nitrate
• zinc nitrite
• zinc(I) nitrate

Answer explanation

Zinc has a fixed +2 charge → no Roman numeral.

Write the formula for iron(III) sulfide.

Answer explanation

Fe³⁺, S²⁻ → Crisscross: Fe₂S₃.

Which name is incorrect for the given formula? Fe(NO₃)₂

• iron nitrate
• iron(II) nitrate
• iron(I) nitrate
• iron(II) nitrite
• iron dinitrate

Answer explanation

Fe(NO₃)₂ has iron +2, so “iron(I)” is incorrect.