During phase changes the signs for ΔH and ΔS are the same.
Breaking bonds requires absorbing energy (+ΔH) and increasing disorder (+ΔS)
Forming bonds requires releasing energy (- ΔH) and decreasing disorder (- ΔS)
Sublimation: phase transition from solid to gas state. Need energy to melt solid into gaseous form which means this is an endothermic process, so ΔH will be positive. Disorder increases as we transition from solid --->liquid---->gas, ΔS will be positive as well...
For each phase change, determine the sign of ΔH and ΔS.
Sublimation ,Freezing, Condensation, Deposition, Boiling , Melting
b) -ΔH, -ΔS
c) +ΔH, -ΔS
d) -ΔH, +ΔS
Put the phase change to the correct sign of ΔH and ΔS
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