1. Quantifying Heat
The Math!

2. q = mCΔT Equation change in temperature, measured in °C
ΔT = Tfinal – Tinitial
heat energy – measured in joules (J)
heat capacity – how much heat a substance can hold, measured in joules/gramdegrees Celsius
mass - measured in grams (g)

3. Units for heat (q)
Most food tells us the amount of energy in units of Calories
Calories are kilocalories (1 Cal = 1000cal)
The SI unit for energy is Joules (J)
1 cal = J
Let’s do some quick conversions.

4. How can you tell if a process is endothermic or exothermic?
q is a positive number
Why?
The final temperature is higher than the initial temperature- we added heat to the system.
ΔT = Tfinal – Tinitial
q is a negative number
Why?
The final temperature is lower than the initial temperature- heat was given off from the system.
ΔT = Tfinal – Tinitial
Let’s solve some problems!