Answer:
<h2>92%</h2>
Explanation:
When glucose is converted to ethanol by yeast, one mole of glucose is converted into two moles of ethanol and two moles of carbon dioxide,
and this process produce two moles of ATP.
C6H12O6 → 2 C2H5OH + 2 CO2
When glucose is converted to ethanol by yeast (as in the production of beer) 92% of the chemical energy that was originally stored in glucose still remains in the end product, ethanol, that is produced.
Lack of water would have an impact on the level of glucose produced hence decreasing the energy level that will finally be produced.