(20 marks) The characteristic odour of pineapple is due to ethyl butyrate, a compound containing carbon, hydrogen and oxygen. Combustion of 2.78 g of ethyl butyrate leads to the formation of 6.32 g of carbon dioxide and 2.58 g of water. a) What is the empirical formula of ethyl butyrate?

b) Some other tests indicate that the molar mass of the compound is between 100 and 150 g/mol. What is the molecular formula?