Crude Oil, Hydrocarbons & Alkanes Flashcards

All 6 cards in this deck

What is crude oil?

A finite resource found in rocks, formed from the remains of an ancient biomass (mainly plankton) buried in mud.

What is a hydrocarbon?

A molecule made up of hydrogen and carbon atoms only.

True or false? Crude oil is a single compound.

False. Crude oil is a mixture of a very large number of compounds, most of which are hydrocarbons.

What is the general formula for the homologous series of alkanes?

$\mathrm{C_nH_{2n+2}}$

Name the first four alkanes in order and give their molecular formulae.

Methane $\mathrm{CH_4}$, ethane $\mathrm{C_2H_6}$, propane $\mathrm{C_3H_8}$, butane $\mathrm{C_4H_{10}}$.

How do you check whether a hydrocarbon is an alkane from its molecular formula?

e.g. is $\mathrm{C_6H_{14}}$ an alkane?

1. Count the carbons: $n = 6$
2. Work out $2n+2$: $2\times6+2 = 14$
3. Compare with the hydrogens given: 14 = 14, so yes, it is an alkane.