<span>D) the Mass of water needs to be in a closed system to control the boiling. With an open system, you can no longer measure the water vapor output and be sure that the water vapor in the bottle is equal to the water vapor in the air or beyond. It is only through the closed system that you can measure the volume, the mass difference and ensure that both are in equilibrium</span>
12 - 15x = -6
to isolate x, we will subtract 12 from both sides
-15x = -18
now we will divide both sides by -15
x=18/15
x=6/5
