How much heat is needed to rise the temperature of 72g of water by 80^c?

Mass of water = 72 g = 72 / 1000 = 0.072 kg

Temperature rise = 80°C

Heat gained = mcθ

Where m = mass in kg, c is specific heat capacity of water = 4200 J/kg°C

θ = Temperature rise.

Heat gained = mcθ

= 0.072 * 4200 * 80 = 24192

So heat needed = 24 192J.