they are called The 7 Seas
Answer : The volume of 
produced at standard conditions of temperature and pressure is 0.2422 L
Explanation :
Combined gas law is the combination of Boyle's law, Charles's law and Gay-Lussac's law.
The combined gas equation is,
where,
= initial pressure of 
gas = (740-22.4) torr = 717.6 torr
= final pressure of gas at STP= 760 torr
= initial volume of gas = 280 mL
= final volume of gas at STP = ?
= initial temperature of gas = 
= final temperature of gas = 
Now put all the given values in the above equation, we get:
Therefore, the volume of produced at standard conditions of temperature and pressure is 0.2422 L
Moles of NaN3 at STP = volume of gas / 22.4 = 11.5/22.4 = 0.5mole. Massof NaN3 = moles of NaN3 x molecular weight = 0.5 x 65 = 32.5 grams.
Because you are never adding more than the substances created, nor are you creating any, but should a chemical reaction take place you could see the liquid change form into a gaseous state and that would result a loss of the liquid volume.
So to wrap it all up you can’t have more liquids than what is already there but you could always lose some due to a chemical change, hence the reason it says an open flask, the chemical change would not be collected, mass would be lost
