Question

Complete combustion of 6.70 g of a hydrocarbon produced 20.7 g of co2 and 9.51 g of h2o. what is the empirical formula for the hydrocarbon? insert subscripts as necessary.?

Answer 1

The empirical formula for the hydrocarbon is
`\( \text{C}_2\text{H}_5 \).`

Step-by-step explanation:

To determine the empirical formula of the hydrocarbon, we first find the moles of carbon and hydrogen in the products (CO₂ and H₂O).

1. Moles of Carbon (C):

From 20.7 g of CO₂, we can calculate moles of carbon using the molar mass of carbon dioxide.

`\[ \text{Moles of C} = \frac{\text{Mass of CO}_2}{\text{Molar Mass of CO}_2} \]`

`\[ \text{Moles of C} = \frac{20.7 \, \text{g}}{44.01 \, \text{g/mol}} \]`

2. Moles of Hydrogen (H):

From 9.51 g of H₂O, we can calculate moles of hydrogen using the molar mass of water.

`\[ \text{Moles of H} = \frac{\text{Mass of H}_2\text{O}}{\text{Molar Mass of H}_2\text{O}} \]`

`\[ \text{Moles of H} = \frac{9.51 \, \text{g}}{18.015 \, \text{g/mol}} \]`

3. Empirical Formula:

The ratio of moles of C to H gives the empirical formula. Normalize the ratio, and if necessary, multiply to obtain whole numbers. In this case, the ratio is approximately 2:5, resulting in the empirical formula
`\( \text{C}_2\text{H}_5 \).`

In summary, by calculating the moles of carbon and hydrogen from the given masses of CO₂ and H₂O and determining their ratio, we find that the empirical formula for the hydrocarbon is
`\( \text{C}_2\text{H}_5 \).`