Chemistry · 9. Thermochemistry

9.2Energy Basics

Section · module m68724

What this needs

Learn these first — this section will not make sense without them.

Nothing in the algebra book is a prerequisite for this section.

What this touches

Algebra that turns up here. Not a blocker, but this is where you will see it used.

  • ΔT is defined as Tfinal − Tinitial, a signed subtraction — reverse the order and a substance that gained heat (q positive, endothermic) reads as though it lost it, even though nothing about the physical process changed.

  • q = c×m×ΔT is a literal formula in four quantities; the ‘Determining Other Quantities’ example isolates c from 6640 J = c×(348 g)×(21.2 °C), the same rearrange-and-solve-for-a-letter move as any formula application.