When P1/P2 = C1/C2
and C is the molarity which = moles/volume
so, P1/P2 = [(mass1/mw)/volume] / [(mass2/mw)/volume]
P1/P2 = (mass1/mw)/1.5L / (mass2/mw)/1.5L
so, Mw and 1.5 L will cancel out:
∴P1/P2 = mass1 / mass2
∴ mass 2 = mass1*(P2 / P1)
= 0.278g * (78 bar / 62 bar)
= 0.35 g
∴ the quantity of argon that will dissolve at 78 bar = 0.35 g
The answer to the question asked above is that in a Molecular Solid, the substance just dissolves into the solution when added to water but ionic solid does not.
Hope my answer would be a great help for you. If you have more questions feel free to ask here at Brainly.
About 2 gallons. (I got 1.92592592593)
