So you have 724 mL (cm3) of C2H12O6, but during the reaction 12% turns to C2H2OH giving you about 87.6mL of ethanol (C2H2OH)
Since the density of ethanol is given we can find the about of moles produced
and use the balanced equation to find the amount of CO2 produced and then use
the gas laws to determine the pressure of the gas in atm.
86.88mL ethanol * 0.79 g/cm3 = 68.6352g
ethanol
ethanol has a molar mass of 46.068 g/mole so,
68.6352g ethanol / 46.068 g/mole = 1.489867 moles ethanol
the share of ethanol to CO2 is given as 1:1 per the reaction equation so the similar
amount of CO2 is formed.
using the gas laws we can now find the pressure of co2
P=(nRT)/V
plugging in we get the following:
((0.0821 L*atm/K*mol)*(1.489867 moles CO2)*(273+29 K)/(.825L)
since the equation requires consistency in units we convert degrees C to K by
adding 273, and dividing our volume of the bottle by 1000 to get the amount of
liters.
the answer should be 44.7758308 atms.