A hydrocarbon sample was burned in a bomb calorimeter. The temperature of the calorimeter and the 1.00 kg of water rose from 20.45°C to 23.65°C. The heat capacity of the calorimeter, excluding the water, is 2.21 kJ/°C. determine the heat released by the combustion.
Add the values of
M*C*(delta T) for the water and the calorimeter. That will give you the answer.
C is the specific heat and delta T is the temperature change. M is the mass.
For the calorimeter, they tell you what the product M*C (the heat capacity) is, so you don't need to know the mass.
13.3
To determine the heat released by the combustion, you need to use the equation:
q = m * C * ΔT
Where:
- q is the heat energy released by the combustion (in Joules or calories)
- m is the mass of the water being heated (in kilograms or grams)
- C is the specific heat capacity of water (4.18 J/g°C or 4.18 kJ/kg°C, depending on the units used)
- ΔT is the change in temperature of the water (in °C)
In this case, we are given the mass of the water (1.00 kg), the specific heat capacity of the calorimeter (2.21 kJ/°C), and the change in temperature (from 20.45°C to 23.65°C). To use the equation above, we need to convert the temperature change to Kelvin.
ΔT = 23.65°C - 20.45°C = 3.20°C
Now, we can convert ΔT from Celsius to Kelvin by adding 273.15:
ΔT = 3.20°C + 273.15 = 276.35 K
Now, you can plug all the values into the equation to calculate the heat energy released:
q = (1.00 kg) * (4.18 kJ/kg°C) * (276.35 K)
q = 1.156 kJ
Therefore, the heat released by the combustion is approximately 1.156 kilojoules.