Number of moles:
n = sample mass / molar mass
n = 15.00 / 74.6
n = 0.2010 moles of KCl
Therefore:
Molarity = moles / Volume
0.1107 = 0.2010 / V
V = 0.2010 / 0.1107
V = 1.815 L
1.melting
2.freezing
3.condensation
4. evaporation
5.sublimation
I've done this a few times and keep coming up with 5.0 L . I used the mole ratio, and SO 2 as the LR. That would make 2 moles of SO3 5.0 L but its not one of your choices. the temp and pressure are constant, so according to n/v = p/rt the volume is the same as the moles. hope this helps