A student has a sample of a liquid.
State a physical test the student can perform to find out if the liquid is a pure substance.
The student finds out that the sample is a mixture containing octane, C8H18\text{C}_8\text{H}_{18}C8H18, and cyclooctane, C8H16\text{C}_8\text{H}_{16}C8H16.
What is the empirical formula of octane?
The boiling point of octane is lower than the boiling point of cyclooctane.
Describe a method the student could use to obtain a sample of pure octane from the mixture of cyclooctane and octane.
The student obtains 14.5 g14.5\text{ g}14.5 g of octane from 18.6 g18.6\text{ g}18.6 g of the mixture.
Calculate the percentage of octane obtained. Give your answer to 2 significant figures.
Octane reacts with oxygen in a complete combustion reaction. Complete the balanced symbol equation for this reaction:
2C8H18+‾O2→‾CO2+‾H2O2\text{C}_8\text{H}_{18} + \underline{\quad\quad}\text{O}_2 \rightarrow \underline{\quad\quad}\text{CO}_2 + \underline{\quad\quad}\text{H}_2\text{O}2C8H18+O2→CO2+H2O