Physics: Specific Heat Capacity
Physics: Specific Heat Capacity
Specific Heat Capacity Basics
- Specific Heat Capacity refers to the amount of heat required to raise the temperature of 1kg of a substance by 1°C. It is expressed in joules per kilogram per degree Celsius (J/kg°C).
- Specific heat capacity is a property of a substance and different substances have different specific heat capacities. For example, water has a relatively high specific heat capacity.
Understanding and Calculating Specific Heat Capacity
- The formula for calculating specific heat capacity is q = mcΔT, where ‘q’ is the heat energy transferred, ‘m’ is the mass of the substance, ‘c’ is the specific heat capacity, and ‘ΔT’ is the change in temperature.
- To find ‘c’ in an unknown substance, you can rearrange the formula to: c = q/(m*ΔT).
Uses of Specific Heat Capacity
- Understanding specific heat capacity is critical in many areas of science and engineering. For instance, it is used in calculations related to climate science, engineering systems, and material selection based on heat resistance or retention.
Experimental Techniques in Specific Heat Capacity
- When doing an experiment to determine a substance’s specific heat capacity, it’s vital to control all other variables so only the factor you’re investigating (i.e., heat input or temperature change) is changing.
- Thermometers or thermocouples are generally used to measure temperature changes, while a calorimeter can be used to measure the amount of heat absorbed or released.
- Common substances to experiment with include metals like copper, aluminium, and lead due to their handy characteristics and easy availability.
- You will need a method to accurately measure the heat added to the system. An electric heater with a joulemeter is a straightforward method to do this.
- Always observe necessary safety measures. For example, handling hot substances with care or protecting your eyes when there’s risk of flying particles.
- Data recording should be precise and careful. Multiple trials should be conducted to ensure an accurate average. Knowing potential sources of error and how to mitigate them, such as heat loss to the surroundings or inaccurate temperature readings, is a critical aspect of this type of experiment.
- Graphing temperature change against energy transferred may result in a straight line whose slope can give the specific heat capacity using the equation ΔT = (q/mc), ‘c’ being the slope.