Calculating Heat Required to Heat Paraffin

Understanding how to calculate the heat required to heat a substance is a fundamental concept in thermodynamics. In this article, we will go through a detailed example of how to calculate the heat required to heat paraffin given specific conditions. Specifically, we will consider the scenario where 2 kg of paraffin needs to be heated through 10°C when the specific heat is given as 2000 J/kg°C.

Understanding Specific Heat and Heat Calculation

The specific heat capacity of a substance is the amount of heat energy required to raise the temperature of 1 kg of the substance by 1°C. The formula to calculate the heat, Q, required to change the temperature of a substance is:

Q mct, where:

Q is the heat energy (in joules, J) m is the mass of the substance (in kilograms, kg) c is the specific heat capacity (in J/kg°C) t is the change in temperature (in degrees Celsius, °C)

Given Conditions and Calculation

In this example, we have the following given conditions:

Specific heat capacity of paraffin, c 2000 J/kg°C Mass of paraffin, m 2 kg Change in temperature, t 10°C

Using the formula Q mct, we can calculate the heat required:

    Q  2 kg x 2000 J/kg°C x 10°C    Q  40000 J    

Expressing this in kilojoules (kJ), we have:

    Q  40000 J  40 kJ    

Verifying the Calculation

Let's verify this calculation with another method to ensure accuracy:

    Heat capacity  2000 J/kg°C    m  2 kg    t  10°C    Q  mCt    Q  2 kg x 2000 J/kg°C x 10°C    Q  40000 J    

Or, expressing it in kJ:

    Q  40000 J  40 kJ    

Conclusion

The calculated heat required to heat 2 kg of paraffin through a temperature change of 10°C is 40000 J or 40 kJ. It is important to understand the principles of specific heat and how to apply the heat calculation formula in various scenarios. This knowledge is crucial in fields such as engineering, chemistry, and physics.