The energy content of food is typically determined using a bomb calorimeter. Consider the combustion of a 0.22-g sample of butter in a bomb calorimeter having a heat capacity of 2.67 kJ/°C. If the temperature of the calorimeter increases from 23.5°C to 26.1°C, calculate the energy of combustion per gram of butter. Energy of combustion = kJ/g

Respuesta :

Answer: The energy of combustion of butter is 31.5 kJ/g

Explanation:

The quantity of heat required to raise the temperature of a substance by one degree Celsius is called the specific heat capacity.

[tex]Q=C\times \Delta T[/tex]

Q = Heat absorbed by calorimeter =?

C = heat capacity of calorimeter = [tex]2.67kJ/^0C[/tex]

Initial temperature of the calorimeter  = [tex]T_i[/tex] = [tex]23.5^0C[/tex]

Final temperature of the calorimeter  = [tex]T_f[/tex]  = [tex]26.1^0C[/tex]

Change in temperature ,[tex]\Delta T=T_f-T_i=(26.1-23.5)^0C=2.6^0C[/tex]

Putting in the values, we get:

[tex]Q=2.67kJ/^0C\times 2.6^0C=6.94kJ[/tex]

As heat absorbed by calorimeter is equal to heat released by combustion of butter

[tex]Q=q[/tex]

Heat released by 0.22 g of butter = 6.94 kJ

Heat released by 1g of butter = [tex]\frac{6.94}{0.22}\times 1=31.5kJ[/tex]

The energy of combustion of butter is 31.5 kJ/g