Souring of wine occurs when ethanol is converted to acetic acid by oxygen by the following reaction:

c2h5oh + o2 --> ch3cooh + h2o

a 1.00 l bottle of wine, labeled as 8.5% (by volume) ethanol, is found to have a defective seal.
analysis of 1.00 ml showed that there were 0.0274 grams of acetic acid in that 1.00 ml. the density of ethanol is 0.816 g/ml and the density of water is 1.00 g/ml.

a. what mass of oxygen must have leaked into the bottle?

b. what is the percent yield for the conversion of ethanol to acetic acid if o2 is in excess?