The combustion of 0.1572 g benzoic acid increases the temperature of a bomb calorimeter by 2.52°C. Calculate the heat capacity of this calorimeter. (The energy released by combustion of benzoic acid is 26.42 kJ/g.)
What is the heat capacity in kJ/C? = 1.65 kJ/C
A 0.2197-g sample of vanillin (C8H8O3) is then burned in the same calorimeter, and the temperature increases by 3.28°C. What is the energy of combustion per gram of vanillin?
Energy in kJ/gram?
I know how to find the heat capacity, but I keep getting the energy incorrect.
Sorry I didn't mean to repost this!
To calculate the energy of combustion per gram of vanillin, you need to use the concept of heat capacity. The heat capacity of the calorimeter (C) can be determined using the given information about benzoic acid: the mass of benzoic acid (m) is 0.1572 g, the temperature increase (ΔT) is 2.52 °C, and the energy released by combustion of benzoic acid (E) is 26.42 kJ/g.
First, calculate the energy released by the combustion of benzoic acid in the calorimeter:
Energy released (E) = mass of benzoic acid (m) × energy released per gram (26.42 kJ/g)
E = 0.1572 g × 26.42 kJ/g
Next, determine the heat capacity of the calorimeter:
Heat capacity (C) = E / ΔT
Substitute the values into the equation:
C = (0.1572 g × 26.42 kJ/g) / 2.52 °C
Now that you have calculated the heat capacity (C) of the calorimeter, you can determine the energy of combustion per gram for vanillin. Let's denote it as E_van:
Energy of combustion per gram of vanillin (E_van) = C × ΔT / mass of vanillin
Given the mass of vanillin (m_van) as 0.2197 g and the temperature increase (ΔT) as 3.28 °C, substitute these values into the equation:
E_van = (C × ΔT) / m_van
E_van = (1.65 kJ/°C × 3.28 °C) / 0.2197 g
Now calculate the energy of combustion per gram of vanillin:
E_van = 4.20 kJ/g
Therefore, the energy of combustion per gram of vanillin is 4.20 kJ/g.