How much heat is required to raise the temperature of 0.25 kg of water from 20C to 30C?

q = m x C x ΔT

q = amount of heat energy gained or lost by substance in Joules

m = mass of sample in grams = 20g

C = heat capacity (J/g•oC) = 4.184 J/g•oC

Tf = final temperature = 55 oC

Ti = initial temperature = 5 oC

ΔT = (Tf - Ti) = (55 oC - 5 oC) = 50 oC

q = 20g x 4.184J/g•oC x 50 oC = 4184 Joules