Introduction to Organic Chemistry: Answers
Define the term hydrocarbon.
A hydrocarbon is a molecule made up of only carbon and hydrogen atoms.
Write the structural formula of butanoic acid.
Any molecule which begins with but- means it has four carbons in its chain. The ending ‘oic acid’ tells us that it is a carboxylic acid (-COOH). Remember that the structural formula is where you write out the atoms in the molecule like a list. Therefore, the structural formula for butanoic acid is: CH3CH2CH2COOH.
What is the empirical formula of hexane?
The empirical formula tells you the simplest whole number ratio of atoms of each element in a compound. The molecular formula of hexane is C6H14. To convert the molecular formula into the empirical formula, we need to see if these numbers can both be divided into something smaller. 6 and 14 are both divisible by two. Dividing the molecular formula by 2 gives us C3H7.
What is an isomer?
Isomers are molecules with the same molecular formula but different structural formula. This means that they have the same number of each type of atom but their atoms are arranged differently within the molecule. Be careful not to confuse isotopes with isomers,
Name the first six molecules in the alkene homologous series.
Use the phrase ‘monkeys eat peeled bananas’ to help you remember how to name the first four compounds: methene, ethene, propene, butene. The next two are easier to remember: pentene and hexene.
What type of functional group is present in ethanol?
Ethanol has the alcohol functional group (-OH).
What type of isomers are hexane and 2,3-dimethylbutane?
Hexane and 2,3-dimethylbutane are chain isomers. They both have the same number of carbon and hydrogen atoms but in hexane these are arranged in one long chain whereas 2,3-dimethylbutane has some carbon atoms coming off the main chain as side branches.