Question

Which formula is both a molecular and an empirical formula?

(1) C6H12O6 (3) C3H8O
(2) C2H4O2 (4) C4H8

Answer 1

3 C3H8O
because you cannot divide the subscripts anymore. The molecular formula is in it's simplest form. And C3H8O is a molecule as well.

Answer 2

Answer : The correct option is, (3)
`C_3H_8O`

Explanation :

Empirical formula : It is defined as the simplest or most reduced ratio of atoms in a compound.

Molecular formula : It is defined as the how many atoms of each element present in a compound.

From the given options, the option (3)
`C_3H_8O` formula represent both a molecular and an empirical formula.

From
`C_3H_8O` formula, we can determine the molecular formula by multiplying the whole numbers (1, 2, 3, 4 ....etc.)

While the other options, (1), (2) and (4) do not represent both a molecular and an empirical formula. Only represent the molecular formula.

The molecular formula of Glucose is,
`C_6H_(12)O_6` and the empirical formula will be,
`C_1H_2O_1`

The molecular formula of Ethanoic acid is,
`C_2H_4O_2` and the empirical formula will be,
`C_1H_2O_1`

The molecular formula of Butene is,
`C_4H_8` and the empirical formula will be,
`C_1H_2`

Hence, the formula represent both a molecular and an empirical formula is,
`C_3H_8O`