Answer:
130
Explanation:
This is because that 3atm of N2O4 is used up for the 6atm of NO2, so 1 atm N2O4 is left. Resulting in In(1/4).
In the dark waters just below the photic zone, because of cellular respiration, the concentration of dissolved carbon dioxide is higher relative to dissolved oxygen.
In cellular respiration living organisms use oxygen and release carbon dioxide, because there is little or no light there is no photosynthesis and oxygen is little produced.
You would use the formula:
n =

Where m is the mass, and M is molar mass (the periodic table would be used for this)
In this case, we need to rearrange the formula to find m
m = nM
= 5.40 x 6.941
= 37.5g
Hope this helped! Ask me if there's any part of the working you don't understand :)