Classify the following phase changes by the signs of the system\'s ?H and ?S

solid-gas
solid-liquid

#1

Classify the following phase changes by the signs of the system’s ?H and ?S.

?H=+ and ?S=+, ?H+= and ?S= - , ?H= - and ?S=+, ?H= - and ?S= -

solid to gas
solid to liquid
liquid to gas
liquid to solid
gas to solid
gas to liquid

Answer:

solid to gas ?H=+ and ?S=+
solid to liquid ?H=+ and ?S=+
liquid to gas ?H=+ and ?S=+
liquid to solid ?H= - and ?S= -
gas to solid ?H= - and ?S= -
gas to liquid ?H= - and ?S= -