Question

A serving of Cheez-Its releases 130 kcal (1 kcal = 4.18 kJ) when digested by your body. If this same amount of energy were transferred to 2.5 kg of water at 27˚C, what would the final temperature be?

Answer 1

The final temperature : 78.925°C

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

Energy releases = 130 kcal = 130 x 4.18 kJ=543.4 kJ

The final temperature :

`\tt \Delta T=(Q)/(m.c)\\\\\Delta T=(543.4)/(2.5* 4.186~kJ/kg^oC)\\\\\Delta T=51.925^oC`

Final temperature :

ΔT=final-initial

51.925°c=final-27°c

final = 51.925+27=78.925°C