Chemistry / Unit 4 Chem 0691 short lesson, about 20 seconds
Standard State and ΔH°
Captions available
The idea
A standard state is a fixed reference condition, materials at 1 bar and solutions at 1 M, and ΔH° marks a change under it.
In practice
A table listing ΔH° values for many reactions lets chemists compare them on one shared footing, regardless of when each was measured.
Where people slip
ΔH°, carrying its standard-state superscript, and an ordinary ΔH under unstated conditions are not interchangeable labels.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
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