Final answer:
When 2.7 moles of ethanol are burned completely, 145.8 grams of water are produced, based on the stoichiometry of the combustion reaction and the molar mass of water.
Step-by-step explanation:
To determine how many grams of water will be produced when 2.7 moles of ethanol are burned completely, we first need to know the balanced chemical equation for the combustion of ethanol:
C2H5OH + 3O2 → 2CO2 + 3H2O
According to the balanced equation, for every mole of ethanol that reacts, 3 moles of water (H2O) are produced. Therefore, if 2.7 moles of ethanol are burned:
2.7 moles of ethanol * 3 moles of water/mole of ethanol = 8.1 moles of water.
The molar mass of water is approximately 18 g/mol. So, the mass of water produced is:
8.1 moles of water * 18 g/mol = 145.8 grams of water.