1. When discussing refluxing, make sure you can explain both the heating and the use of reflux. ie, with esterification, heat to:
* increase the rate of reaction - alcohol + carboxylic acid esterifications arre generally slow
* increase the yield - HSC esterifications are endothermic equilibrium processes, and so heating drives the reaction to the right (Le Chatelier's Principle)
Having decided to heat, the presence of volatile (easily vapourised) materials makes the use of a reflux apparatus essential, to prevent their loss.
2. Xayma has explained with the MF is C<sub>4</sub>H<sub>8</sub>O<sub>2</sub>, so I'll just address part (c). The question mentions a fruity smell - this means that the product is almost certainly an ester. The possible esters with this molecular formula are:
methyl propanoate: CH<sub>3</sub>CH<sub>2</sub>-C(=O)-O-CH<sub>3</sub>
ethyl ethanoate: CH<sub>3</sub>-C(=O)-O-CH<sub>2</sub>CH<sub>3</sub>
propyl methanoate: H-C(=O)-O-CH<sub>2</sub>CH<sub>2</sub>CH<sub>3</sub>
2-propyl methanoate: H-C(=O)-O-CH(CH<sub>3</sub>)<sub>2</sub>
3. Boiling Chips (or anti-bumping granules) are included prmarily as a safety measure. They prevent the liquid from superheating, and thus prevent bumping. They do serve other functions (like helping with the uniformity of heating, as Xeriphic suggests), but the safety feature is their major role.
4. No. The alkanes - methane, ethane, propane, butane, ... - are a homologous series, as are the primary alkanols - methanol, ethanol, 1-propanol, 1-butanol, ..., and the alkanoic acids - methanoic acid, ethanoic acid, propanoic acid, ... So, methane, methanol and methanoic acid belong to different homologous series. A simple way to think of a homologous series is that it can be represented by a general formula, ie:
alkanes: C<sub>n</sub>H<sub>2n+2</sub>, n = 1, 2, 3, ...
primary alkanols: C<sub>n</sub>H<sub>2n+1</sub>OH, n = 1, 2, 3, ...
alkanoic acids: C<sub>n</sub>H<sub>2n+1</sub>COOH, n = 0, 1, 2, ...
AND that each member differs from the preceeding member by a CH<sub>2</sub> unit