International General Certificate of Secondary Education (IGCSE) Chemistry Practice Exam

What is the raw material needed for the manufacture of ethanol through the fermentation of sugars?

1. Crude oil

2. Ethene

3. Sugar cane

4. Water

The correct answer is: Sugar cane

The manufacture of ethanol through the fermentation of sugars primarily requires a source of sugar, which in this context, is sugar cane. Sugar cane is a plant that contains high concentrations of sucrose, a type of sugar that can be easily fermented by yeast to produce ethanol and carbon dioxide. During fermentation, yeast converts the sugars present in sugar cane into ethanol, making it a crucial raw material in this process. While other substances such as water are necessary for the fermentation process, they are not the primary raw material used to create the ethanol itself. Crude oil and ethene do not play a role in biological fermentation processes, as they pertain instead to petrochemical methods of producing ethanol, which are different from fermentation with sugars. Thus, the correct answer is indeed sugar cane, as it directly provides the sugars necessary for the fermentation to produce ethanol.