Balanced Chemical Equation:
The balanced chemical equation for the combustion of C2H5OH (ethanol) in air is as follows:
C2H5OH + 3O2 → 2CO2 + 3H2O

Given Information:
- Moles of C2H5OH = 0.274 mole

Calculations:
To determine the moles of CO2 obtained when 0.274 mole of C2H5OH is burnt in air, we need to use the balanced chemical equation.

From the balanced equation, we can see that 1 mole of C2H5OH reacts to form 2 moles of CO2. Therefore, we can set up a proportion to find the moles of CO2:

(0.274 mole C2H5OH) * (2 mole CO2 / 1 mole C2H5OH) = 0.548 mole CO2

Therefore, when 0.274 mole of C2H5OH is burnt in air, we obtain 0.548 mole of CO2.

Explanation:
When C2H5OH is burnt in air, it undergoes combustion, a chemical reaction that involves the combination of a substance with oxygen to produce heat and light. In this case, ethanol (C2H5OH) reacts with oxygen (O2) in the air to produce carbon dioxide (CO2) and water (H2O).

The balanced chemical equation shows that for every molecule of C2H5OH burnt, two molecules of CO2 are produced. This means that the ratio of moles of C2H5OH to moles of CO2 is 1:2.

To calculate the moles of CO2 obtained, we can use the given information of 0.274 mole of C2H5OH and set up a proportion. By multiplying the given moles of C2H5OH by the mole ratio of CO2 to C2H5OH (2 moles CO2 / 1 mole C2H5OH), we can determine the moles of CO2 obtained.

Therefore, when 0.274 mole of C2H5OH is burnt in air, 0.548 mole of CO2 is obtained.