Answer
See explanation below.
Work Step by Step
1
Ba(s) > Ca(s) > Mg(s)
heavier atom has higher entropy
2
C6H14 > C6H12 > C6H6
with decreasing flexibility molar entropy decreases
3
PF2Cl3(g) > PF5(g) > PF3(g)
PF5(g) > PF3(g)
Molar entropy increases with increasing molecular complexity
PF2Cl3(g) > PF5(g)
Because Cl is heavier atom than F hence more molar entropy