Summary of Differences
| Property | Heat Capacity | Specific Heat |
|---|---|---|
| Definition | Heat required to raise temperature of an object by 1°C | Heat required to raise 1 kg of a substance by 1°C |
| Unit | Joules per degree Celsius (J/°C) or (J/K) | Joules per kilogram per degree Celsius (J/kg·°C) |
| Dependence on Quantity | Depends on the amount of material | Independent of the amount of material |
| Application | Used for objects or systems | Used for materials and their properties |
| Formula | Q=C⋅ΔTQ = C \cdot \Delta T | Q=m⋅c⋅ΔTQ = m \cdot c \cdot \Delta T |
Heat capacity and specific heat are both terms used to describe the thermal properties of materials, but they refer to different concepts. Here’s a breakdown of their differences:
1. Definition
- Heat Capacity:
Heat capacity is the amount of heat energy required to raise the temperature of an object or system by 1 degree Celsius (or 1 Kelvin). It is an extensive property, meaning it depends on the size or amount of material in the system.Formula:
Q=C⋅ΔT
Where:- Q = heat energy absorbed or released
- C = heat capacity
- ΔT = change in temperature
- Specific Heat (Specific Heat Capacity):
Specific heat is the amount of heat energy required to raise the temperature of 1 kilogram of a substance by 1 degree Celsius (or 1 Kelvin). It is an intensive property, meaning it does not depend on the amount of material but on the type of substance.Formula:
Q=m⋅c⋅ΔT
Where:- Q = heat energy absorbed or released
- m = mass of the substance
- c = specific heat
- ΔT = change in temperature
2. Units
- Heat Capacity: The unit of heat capacity is Joules per degree Celsius (J/°C) or Joules per Kelvin (J/K).
- Specific Heat: The unit of specific heat is Joules per kilogram per degree Celsius (J/kg·°C) or Joules per kilogram per Kelvin (J/kg·K).
3. Dependence on Quantity
- Heat Capacity: Depends on the amount of material in the system. The larger the object, the higher the heat capacity, as more heat is needed to raise its temperature by 1°C.
- Specific Heat: Does not depend on the quantity of material, only on the substance itself. Different materials have different specific heats, which is why water, for example, has a high specific heat compared to metals.
4. Application
- Heat Capacity: Used when considering the heat required to change the temperature of an entire object, like a metal block or a body of water.
- Specific Heat: Used when comparing the heat capacities of different substances per unit mass. It is essential for determining how much energy is required to change the temperature of a specific mass of a material.
5. Relationship Between Heat Capacity and Specific Heat
- Formula:
Heat capacity (CC) is related to specific heat (cc) by the formula: C=m⋅c
Where:- C is the heat capacity
- m is the mass of the material
- c is the specific heat of the material
Conclusion
Heat capacity measures the total heat required for an object’s temperature change, whereas specific heat measures the heat needed for temperature changes per unit mass of a material. Understanding both concepts is essential for thermodynamic calculations and practical applications in fields like chemistry, engineering, and physics.
