Empirical Formulas

What is the empirical formula if you have 36.84% nitrogen and 63.16% oxygen?

• NO
• N₂O₃
• N₂O₄
• N₂O₅

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.

What do you do when you do not get whole numbers in the ratio?

• add 2 to each element

  add two to only the one with the half

• multiply the one with the half only by two

• multiply all of them by two

• add two to all of the ratios

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 if you have 88.80% copper and 11.20% oxygen?

• Cu₃O₈
• CuO₄
• Cu₂O
• Cu₄O₁₀

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

• C₃H₆
• CH₂
• C₂H₄
• CH₃