AlcoholsIB MYP Chemistry: Mind map

Exam questions on Alcohols

1. A teacher writes the formulae CH₃OH, C₂H₅OH, C₃H₇OH and C₄H₉OH on the board and tells her class that they are the first four members of a family of compounds called alcohols.
   Explain why methanol and ethanol have similar chemical properties.2 marks
2. A bioethanol plant in Thailand makes ethanol from the sugar in sugar cane. The sugar solution is fermented in large tanks that are kept at about 30 °C.
   State two other conditions, apart from temperature, that are needed for fermentation to produce ethanol.2 marks
3. A student in Cape Town compares the energy released when four alcohols burn. For each alcohol she burns 0.0050 mol in a spirit burner under a metal can containing 100 cm³ of water, and she measures the temperature rise of the water. The temperature rises were: methanol 6 °C, ethanol 11 °C, propanol 17 °C and butanol 22 °C.
   To make the comparison fair, the student kept some variables the same. Describe two variables that she should control and one safety precaution she should take.3 marks