Question

Question #d3fd1

Answer 1

The molecular formula of `"C"_2"H"_5"` is `color(blue)("C"_4"H"_10"`.

The molecular formula of `"CH"` is `color(blue)("C"_6"H"_6`.

Explanation:

In order to determine the molecular formula from an empirical formula, first determine the empirical formula mass. Then divide the given molecular mass by the empirical formula mass.

`color(blue)("Empirical Formula Mass of C"_2"H"_5"`.

`"C":` `(2xx12"g/mol")="24 g/mol"`

`"H":` `(5xx1"g/mol")="5 g/mol"`

Formula Mass = `"24 + 5 g/mol = 29 g/mol"`

`color(blue)("Molecular Formula of C"_2"H"_5"`

Divide the molecular mass by the empirical mass.

`58/29=2`

Multiply the subscripts in the empirical formula by `2` to get the molecular formula.

`"C"_4"H"_10`

`color(blue)("Empirical Formula Mass of CH"`.

`"C":` `1xx12"g/mol"`

`"H":` `1xx1"g/mol"`

Formula Mass = `"12 g/mol+1 g/mol=13 g/mol"`

Divide the molecular mass by the empirical mass.

`78/13=6`

`color(blue)("Molecular Formula of CH"`.

Multiply the subscripts of `"CH"` by `6`.

`"C"_6"H"_6"`