Are enthalpy and entropy affected by temperature?

Answer 1

They certainly are. Here's how:

#DeltabarS = int_(T_1)^(T_2) (barC_P)/T dT#

#DeltabarH = int_(T_1)^(T_2) barC_P dT#

where #barC_P# is the molar heat capacity in a constant pressure system, and #DeltaS# and #DeltaH# are the change in entropy and enthalpy, respectively.

So, let's say you had water, whose chemistry molar heat capacity is defined as #"75.375 J/mol"*"K"#. Then, we have, from #273# to #"298 K"#:

#DeltabarS = int_("273 K")^("298 K") (barC_P)/T dT#

#= barC_P|[ln|T_2| - ln|T_1|]|_("273 K")^("298 K")#

ln(298) - ln(273) * 75.375*

#color(blue)("= 6.604 J/mol"*"K")#

#DeltabarH = int_("273 K")^("298 K") barC_P dT#

#= barC_P(T_2 - T_1)#

#= 75.375(298 - 273)#

#color(blue)("= 1884.38 J/mol")#

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Answer 2

Kai Bowman

Yes, both enthalpy and entropy are affected by temperature. Enthalpy typically increases with temperature for endothermic reactions and decreases for exothermic reactions. Entropy generally increases with temperature, as higher temperatures lead to greater molecular disorder and randomness in the system.

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Answer 3

Xavier Avery

Yes, both enthalpy and entropy are affected by temperature.

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Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.