Specific Heat Capacity Experiment for Schools, Teachers, and Students
Specific heat capacity is the amount of heat energy required to raise the temperature of a unit mass of a substance by 1°C or 1 K. Mathematically, it is expressed as:
c = Q / (m ΔT)
Where:
- c: Specific heat capacity (J/kg·K or cal/g·K)
- Q: Heat energy supplied (J or cal)
- m: Mass of the substance (kg or g)
- ΔT: Change in temperature (K or °C)
Key Points
- Different substances require different amounts of heat energy to change their temperature due to differences in their specific heat capacity.
- Water has a high specific heat capacity (c = 4200 J/kg·K), which makes it useful for regulating temperatures.
- Metals like copper and aluminum have low specific heat capacities, making them good conductors of heat.
Heat Energy Formula
The amount of heat energy (Q) required to change the temperature of a substance is:
Q = mcΔT
Where:
- Q: Heat energy absorbed or released
- m: Mass of the substance
- c: Specific heat capacity
- ΔT: Temperature change (T_final – T_initial)
Specific Heat of Water
Water has one of the highest specific heat capacities among common substances:
c_water = 4200 J/kg·K
This property allows water to absorb or release large amounts of heat without a significant change in temperature.
Applications of Specific Heat Capacity
- Climate Regulation: Water bodies like oceans and lakes moderate the climate by absorbing and releasing heat slowly.
- Car Radiators: Water is used in radiators to cool engines due to its high specific heat capacity.
- Cooking Utensils: Metals with low specific heat, such as copper and aluminum, are used to heat food quickly.
- Thermal Storage: Substances with high specific heat are used to store heat energy in solar heaters and thermal batteries.
Factors Affecting Heat Energy
The heat energy absorbed or released depends on:
- The mass of the substance (m)
- The specific heat capacity of the substance (c)
- The temperature change (ΔT)
Observations
- Substances with higher specific heat capacities take longer to heat up or cool down.
- Metals, with low specific heat capacity, heat up and cool down quickly.
- Water, due to its high specific heat, is used in applications requiring temperature regulation.
Real-Life Example
If 2 kg of water is heated from 20°C to 70°C, the heat energy absorbed can be calculated as:
Q = mcΔT = 2 × 4200 × (70 – 20) = 420,000 J.
