When .4000 g of CH4 is burned in excess oxygen in a bomb calorimeter that has a heat capacity of 324, the temperature increases 6.795 degrees celsius. How much energy is released? (in kJ/mol CH4)
324 WHAT
To determine the amount of energy released when CH4 is burned, we need to calculate the heat produced and convert it to kilojoules per mole of CH4.
First, we need to calculate the heat produced in the bomb calorimeter. The heat produced (q) is given by the equation:
q = C × ΔT
Where:
- q represents the heat produced (in Joules),
- C represents the heat capacity of the bomb calorimeter (in Joules/degree Celsius),
- ΔT represents the change in temperature (in degrees Celsius).
Given:
- C = 324 Joules/°C,
- ΔT = 6.795 °C.
Plugging in these values, we can calculate the heat produced:
q = 324 J/°C × 6.795 °C
q ≈ 2202.78 J
Next, we need to convert the heat produced in Joules to kilojoules per mole of CH4. To do this, we need to know the molar mass of CH4.
The molar mass of CH4 is:
- C (carbon) = 12.01 g/mol
- H (hydrogen) = 1.008 g/mol
So, the molar mass of CH4 is:
12.01 g/mol (C) + 4(1.008 g/mol) (H) = 16.04 g/mol.
To convert from grams to moles, we use the following equation:
moles = mass / molar mass
For the given sample mass of 0.4000 g CH4:
moles = 0.4000 g / 16.04 g/mol
moles ≈ 0.0249 mol
Now, we can calculate the energy released per mole of CH4:
Energy released = q / moles
Energy released = 2202.78 J / 0.0249 mol
Energy released ≈ 88454.82 J/mol
Lastly, let's convert the energy released from joules to kilojoules:
Energy released ≈ 88.45482 kJ/mol (rounded to five decimal places)
Therefore, approximately 88.45482 kJ/mol of CH4 is released when 0.4000 g of CH4 is burned in excess oxygen in the bomb calorimeter.