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Research is being conducted into the development of new biofuels - VCE - SSCE Chemistry - Question 7 - 2009 - Paper 1
Question 7
Research is being conducted into the development of new biofuels. It is known that a type of bacteria, clostridium acetobutylicum, converts cellulose to butanol. Th... show full transcript
Worked Solution & Example Answer:Research is being conducted into the development of new biofuels - VCE - SSCE Chemistry - Question 7 - 2009 - Paper 1
Step 1
a. Identify one step that represents an overall reduction reaction.
Answer
The step that represents an overall reduction reaction is the conversion of carbon dioxide to glucose. This process involves the addition of electrons (reduction) to carbon dioxide, resulting in the formation of glucose.
Step 2
b. Write a balanced equation for step 4 where, in a single reaction, 1-butanol reacts to form carbon dioxide as one of the products.
Answer
The balanced equation for step 4 can be written as:
ightarrow 4 ext{CO}_2 + 5 ext{H}_2 ext{O}$$ This represents the combustion of 1-butanol producing carbon dioxide and water.Step 3
c. Explain, in terms of the structure of these two molecules, why this is the case.
Answer
Sucrose is a disaccharide formed by the condensation of glucose and fructose. Due to its larger size and the presence of multiple hydroxyl groups, sucrose can form extensive hydrogen bonds with water molecules, making it highly soluble.
In contrast, 1-butanol is a much smaller molecule with only one hydroxyl group. Although it can also form hydrogen bonds, its limited ability to interact with water compared to sucrose results in much lower solubility.
Step 4
d. Why does the breakdown of sucrose require the presence of both water and sucrose?
Answer
The breakdown of sucrose into its constituent monosaccharides requires water (a hydrolysis reaction). This reaction is catalyzed by the enzyme sucrase, which facilitates the cleavage of the glycosidic bond in sucrose. The presence of both reactants is critical because water provides the necessary hydroxyl and hydrogen ions that are used to break the bond, thus allowing the reaction to proceed.