Alcoholic Fermentation by Yeast

Steps:

• Identify the process: Yeast performs alcoholic fermentation to produce ethanol from glucose without oxygen.
• Recall the chemical equation: C6H12O6 → 2C2H5OH + 2CO2.
• Note the reactants and products: Glucose is broken down into ethanol (alcohol) and carbon dioxide.
• Confirm the other product besides alcohol: Carbon dioxide is released as a gas.

Why A is correct:

• In the fermentation equation, CO2 is stoichiometrically produced with ethanol, as per the balanced reaction C6H12O6 → 2C2H5OH + 2CO2.

Why the others are wrong:

• B: Oxygen is not produced; fermentation is anaerobic and consumes glucose without oxygen.
• C: Glucose is the starting reactant, not a product.
• D: Water is not a direct product of alcoholic fermentation.

Final answer: A