Question

Suppose a snack bar is burned in a calorimeter and heats 2,000 g water by 20 °C. How much heat energy was released?

Answer 1

Heat energy released : 167.2 kJ

Further explanation

Heat can be calculated using the formula:  

Q = mc∆T  

Q = heat, J  

m = mass, g  

c = specific heat, joules / g ° C  

∆T = temperature difference, ° C / K  

m = 2000 g

c = 4.18  J/ g ° C  

∆t = 20 ° C  

$\tt Q=2000\times 4.18\times 20\\\\Q=167200~J=167.2~kJ$