How much heat is required to increase the temperature of 100.0 grams of iron from 15.0oC to 40.2oC? (The specific heat of iron is 0.46 J/g xoC).

The formula you need is: heat = specific heat x mass x ΔT

specific heat = 0.46 j/g-C

mass = 100.0 grams

ΔT = 40.2 - 15.0 = 25.2C

heat = (0.46) x (100.0) x (25.2) = 1159.2 joules or 1200 joules (rounded off)