Multiple Choice
Which of the following best describes the difference between the heat (q) of a reaction and the reaction enthalpy (ΔH_{rxn})?
64
views
8. Thermochemistry
Thermochemical Equations
Multiple Choice
Is the dissolution reaction of urea in water enthalpically favored?
A
Yes, because the process releases heat and has a negative enthalpy change.
B
Yes, because the process absorbs heat and has a positive enthalpy change.
C
No, because the process absorbs heat and has a positive enthalpy change.
D
No, because the process releases heat and has a negative enthalpy change.
Verified step by step guidance1
Understand that an enthalpically favored process is one that releases heat to the surroundings, meaning it has a negative enthalpy change (\(\Delta H < 0\)).
Recognize that when a substance dissolves in water, the enthalpy change (\(\Delta H\)) can be either positive (endothermic, absorbs heat) or negative (exothermic, releases heat).
Recall or look up the enthalpy change for the dissolution of urea in water, which is known to be positive, indicating the process absorbs heat from the surroundings.
Since the dissolution of urea absorbs heat, it is not enthalpically favored because \(\Delta H\) is positive, meaning the system requires energy input rather than releasing energy.
Conclude that the correct statement is: the dissolution of urea in water is not enthalpically favored because the process absorbs heat and has a positive enthalpy change.
Related Videos
Related Practice
