<u>Answer:</u> The solubility of
at 12.0 atm is 
Explanation:
We are given:
Mass of
= 27.0 grams
Volume of liquid acetone = 1.00 L
Solubility of
in liquid acetone at 1.00 atm = 27.0 g / 1.00 L
To calculate the molar solubility, we use the equation given by Henry's law, which is:

Or,

where,
are the initial concentration and partial pressure of 
are the final concentration and partial pressure of 
We are given:

Putting values in above equation, we get:

Hence, the solubility of
at 12.0 atm is 