Question

A researcher studying the nutritional value of a new candy places a 5.00-gram sample of the candy inside a bomb calorimeter and combusts it in excess oxygen. The observed temperature increase is 2.77 °C. If the heat capacity of the calorimeter is 47.10 kJ·K–1, how many nutritional Calories are there per gram of the candy?

Answer 1

Answer: 6236.48 cal/gram

Explanation:$Q= c\times \Delta T$

Q= heat released

c = heat capacity of substance $=47.10 kJK^{-1}=47100 JouleK^{-1}= 11.25kcalK^{-1}$      

(1Joule=0.00024kCal)   (1kcal=1000cal)

$\Delta T$=Change in temperature= 2.77C= 2.77K

$Q= 11257.17calK^{-1}\times 2.77K$

$Q= 31182.4cal$

Now heat released per gram of the candy=$\frac{31182.4cal}{5.00g}$

$=6236.48cal/gram$