Answer:
9.28
Explanation:
pOH refers to a measure of hydroxide ions concentration. pOH tells about the alkalinity of a solution. If pOH is less than 7 then aqueous solutions are alkaline, acidic if pOH is greater than 7 and neutral if pOH is equal to 7.
Concentration of the hydroxide ions = 1.9 x 10-5 M
pH = 
pOH = 14 - pH
=14 - 4.72 = 9.28
Coffee is acidic so the first one would be correct
The pressure of gas will increase because gaseous state is the final state and even if the heat added is evaporating some more gas is still added. It also depends on the temperature of heat added, if the temperature doesn't change the it's most likely for the pressure to be stable...
Hope it helps