A-Level Empirical Formula

An empirical formula:

• is a formula that calculates the coefficients of a compound in a balanced equation.
• is the simplest whole-number ratio of moles of elements in the compound.

You are given the following percentages: 40.05% S and 59.95% O. Find the empirical formula for these elements. (keep two decimal places throughout calculations)

• SO
• SO₂
• SO₃
• SO₄

What is the empirical formula of the following molecular formula:  C₃H₆

• C₃H₆
• CH₂
• C₂H₄
• CH₃

What is the empirical formula for a compound containing the following ratio:
3Na:1P:4O

• NaPO₄
• Na₃P₄O
• Na₃PO₄
• NaPO

Tags

NGSS.HS-PS1-1

A compound came out with the following ratio
3 Carbon: 1.49 Phosphorus: 2 Oxygen- what would be the empirical formula?

• Ca₆P₃O₄
• C₃PO₂
• C₆P₃O₄
• C₃P₃O₂

What is the empirical formula for the following:
32.40% sodium, 22.5% sulfur; 45.1 % oxygen, 37.75% water?

• Na₂SO₄H₆O₃
• Na₂SO_{4 .} 2H₂O
• Na₂SO_{4 .} 3H₂O
• Na₂SO_{4 .} (H₂O)₃

Which one is empirical?

• H₂O₂
• C₂H₆O₁₂
• CaCl₂
• N₂O₈

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

• CH₂O
• C₂H₄O₂
• C₄H₈O₄
• C₆H₁₂O₆

Tags

NGSS.HS-LS1-6

What is the molecular formula if the empirical formula is C₂H₅ and the molecular molar mass is 58.14 g/mol?

• C₂H₅
• C₄H₁₀
• C₁H_2.5
• C₄H₈

What is the empirical formula if you have 88.80% copper and 11.20% oxygen?

• Cu₃O₈
• CuO₄
• Cu₂O
• Cu₄O₁₀