Specific heat capacity is a basic concept in thermodynamics and it plays a major role in heat transmission in different substances. It explains how much heat is necessary to change the temperature of a particular substance and is extensively employed in physics, chemistry, and engineering.
Definition of Specific Heat Capacity
Specific heat capacity, commonly called specific heat and it is defined as the amount of heat energy necessary to increase the temperature of one unit mass of a substance by one degree Celsius (or one Kelvin).Mathematically, it is expressed as:
c = Q /mΔT
where:
c = Specific heat capacity (J/kg·K)
Q = Heat energy supplied or removed (Joules)
m = Mass of the substance (kg)
ΔT = Change in temperature (°C or K)
The SI unit of specific heat capacity is J/kg.K (Joule per kilogram per Kelvin).
Explanation and Concept
A substance’s molecular structure and the kind of bonding that exists between atoms or molecules determine its specific heat capacity. To produce the same temperature change, various substances need varying amounts of heat. This difference arises because the atomic and molecular configurations of things affect how they store and distribute heat.
The quantity of heat energy is required to raise the temperature of water, e.g, due to its high specific heat capacity of about 4.18 J/g•K. The ability of water to regulate temperature in both natural and manmade systems. Due to this quality, it is being considered as a great coolant.
Factors Affecting Specific Heat Capacity
The following variables affect a substance’s specific heat capacity:
Material Nature: The molecular structures of various substances influence it then how fine they store and transport the heat.
Phase of the Substance: When a substance transforms from a solid into a liquid or gas, then its specific heat capacity varies.
Temperature: Due to variations in molecular motion, the specific heat capacity can occasionally vary to some extent with temperature.
Pressure: Of course, it has little effect of pressure on solids and liquids, but it has a big impact on gases’ specific heat capacity.
Molar specific heat capacity: It is defined for amount of substance expressed in gram moles. C = S/ù = I ΔQ/ ùΔT
There are two types of molar specific heat capacity:
(i) Molar specific heat capacity at constant pressure (Cp) (ii) Molar specific heat capacity at constant volume (Cv).
Molar heat capacity, or the amount of heat needed to raise the temperature of one mole of a substance by one Kelvin, is used to represent specific heat for gases and compounds that are measured in moles. It is provided by:
Cm= Q /nΔT
where Cm is the molar specific heat capacity and n is the number of moles.
Types of Specific Heat Capacity
There are two categories of specific heat capacity for gases:
The heat required to raise a unit quantity of gas’s temperature at constant volume is known as specific heat capacity at constant volume, or Cv.
The heat needed to increase a unit mass of gas’s temperature at constant pressure is known as the Specific Heat Capacity at Constant Pressure (Cp).
These are related by Mayer’s relation: Cp – Cv = R
Where R is the universal gas constant.
Importance and Applications
There are many useful applications for the concept of specific heat capacity:
Climate and Weather Patterns: Because of their large specific heat capacity, water bodies control temperature, which affects the weather.
Cooking: Depending on their individual heat capabilities, various cooking materials heat up in different ways.
Air conditioning and refrigeration: To transmit heat effectively, refrigerants are selected according to their unique heat properties.
Thermal Engineering: When developing boilers, engines, and other heat-based devices, specific heat is taken into consideration.
Astronomy and Space Science: Studying planetary atmospheres and space missions is made easier with an understanding of specific heat capacity.
1 thought on “Specific Heat Capacity”