Question

which of the following might represent the empirical formula for a compound?
○ c₄h₄o₂
○ ch₁.₅o
○ c₂h₆o₂
○ ch₂o

Explanation:

An empirical formula shows the simplest whole - number ratio of atoms in a compound.

• For \(C_4H_4O_2\), the ratio of \(C:H:O = 4:4:2=2:2:1\), so the empirical formula is \(C_2H_2O\) (not \(C_4H_4O_2\) itself).
• For \(CH_{1.5}O\), sub - scripts in a formula must be whole numbers. We can multiply by 2 to get \(C_2H_3O_2\) (so \(CH_{1.5}O\) is not an empirical formula).
• For \(C_2H_6O_2\), the ratio of \(C:H:O=2:6:2 = 1:3:1\), so the empirical formula is \(CH_3O\) (not \(C_2H_6O_2\) itself).
• For \(CH_2O\), the ratio of \(C:H:O = 1:2:1\) and the sub - scripts are in the simplest whole - number ratio.

Answer:

\(CH_2O\)