How to determine heat in joules

Question

How much heat (in joules) is used to heat a 35.97 gram sample of iron from 12.5 degrees Celcius to 100.00 degrees Celcius if the specific heat of Fe is 0.450 J/g°C?

Answer 1

deltaH = m*Cp*deltaT

m = mass (g)

Cp = specific heat (J/g^oC)

deltaT = change in temperature (^oC)

Note: when calculating the change in temperature, the order is always "finals minus initial"

deltaT = Final T - Initial T

In this case, the change in temperature is 100-12.5 = 87.5 ^oC

Then, we plug in the specific heat and mass into the first equation.

deltaH = (35.97 g) x (0.450 J/g^oC) x (87.5 ^oC)

deltaH = 1420 J