Entropy Quiz

1
Entropy Quiz 5 The normal melting point of Pb
is 327 oC. Answer the questions posed below for
the following phase change 300
oC Pb (s) --------gt Pb (l)
1 atm What is the sign on DSsystem
? D Ssystem gt 0 (liquid is more disordered than
the solid) Which phase of Pb is stable under
these conditions? At temperatures lt the normal
melting point, the solid is stable Is the
direction of spontaneous change in the direction
indicated by the arrow (the forward direction) or
is it in the reverse direction? The direction
of spontaneous change is in the reverse direction
2
What is the sign on DStotal ? D Stotal lt 0,
since the direction of spontaneous
change is the reverse of the indicated
direction What is the sign on DSsurroundings ?
D Ssurrounding D Stotal - D Ssystem ( lt
0 ) - ( gt 0) lt 0