Molar Mass, Empirical and Molecular Formulas

You are given the following percentages: 40.05% S and 59.95% O. Find the empirical formula for these elements.

• SO

• SO₂

• SO₃

• SO₄

Given the following: 42.07% Na, 18.89% P, and 39.04% O, determine the empirical formula.

• NaPO₂

• Na₂PO₃

• Na₃PO₄

• NaPO₄

What is the mass of 0.75 moles of (NH₄)₃PO₄?

• 101.75 g
• 121.75 g
• 111.75 g
• 131.75 g

Determine the amount of moles in CuBr that are in 276.9 g of the compound.

• 3.2 mol

• 1.7 mol

• 2.1 mol

• 1.9 mol

Determine the number of moles of Mg₃P₂ that are in 583 g of the compound.

• 2.9 mol

• 6.1 mol

• 4.3 mol

• 1.7 mol

What is the molar mass of NaCl?

• 28 g/mol

• 58.5 g/mol

• 12 g/mol

• 6.02 x 10²³

A formula with the lowest whole # ratio of elements in a compound is called

• Molecular Formula
• Chemical Formula
• Empirical Formula 
• Distance Formula

A chemical formula that shows the actual # and kinds of atoms present in one molecule of a compound is called_________

• ionic formula
• covalent formula
• empirical formula
• molecular formula

What is the molecular formula if the empirical formula is CH₂O and the molecular molar mass is 180.18?

• CH₂O
• C₂H₄O₂
• C₄H₈O₄
• C₆H₁₂O₆

What is the molecular formula for a compound with the empirical formula: K₂SO₄ and a molecular mass of 696g.

• K₂SO₄ 
• K₈SO₁₆
• K₈S₄O₈ 
• K₈S₄O₁₆