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

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.

Q = Heat absorbed by calorimeter =?

C = heat capacity of calorimeter =

Initial temperature of the calorimeter  = =

Final temperature of the calorimeter  =  =

Change in temperature ,

Putting in the values, we get:

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

Heat released by 0.22 g of butter = 6.94 kJ

Heat released by 1g of butter =

The energy of combustion of butter is 31.5 kJ/g

  the   balanced   equation   for   reaction of   ca metal   with   o2 to   produce   cao   is as below

2 ca+ o2→ 2 cao2

  explanation

the reaction is   balanced     since the   number of atoms   in reactant side is   equal to   number of atoms   in   product side.   for   example   they   are 2   atom of   ca in   reactant   side   and   2   atoms of ca   in   the product side.

  the   process   is a   meet the   requirement   of   redox   reaction because :     calcium   is   oxidized   from   oxidation state 0   to 2+   while   oxygen   is reduced from   oxidation   state   0   to 2-