Get to understand the basic difference between heat and temperature. The basis of comparison include: description, expression, international standard unit of measurement, working ability, negative values, symbol, device used in measuring and nature.
What Is Heat?
In thermodynamics, Heat is energy that flows between a system and its environment by virtue of temperature difference between them. The mechanism includes conduction, through direct contact of immobile bodies, or through a wall or barrier that is impermeable to matter or radiation between separated bodies. When there is a suitable path between two systems with different temperatures, heat transfer occurs necessarily, immediately and spontaneously from the hotter to the colder system. As a form of energy, heat has the unit joule (J) in the international system of units (SI). Here is a highlight description of heat as a form of energy:
- Heat is energy that flows between a system and its environment by virtue of temperature difference between them.
- In thermodynamic, heat is taken to be the total kinetic energy and potential energy obtained by molecules in object.
- Heat being a form of energy, its standard unit of measurement is Joule (J). It can also be measured in calorie (cal) and related to joule according to: 1cal= 4.186 Joules.
- Heat will always travel from a hotter region to a cooler region.
- Heat is measured by a device known as Calorimeter.
- Heat is represented by Symbol of letter (Q).
- Heat has the working ability.
- The thermal energy of a system cannot have negative values.
What Is Temperature?
Temperature is a physical quantity expressing hotness or coldness of a substance. It is measured with a thermometer calibrated in one or more temperature scales. The most commonly used scales are the Celcius scale, Fahrenheit scale and Kelvin scale. The Kelvin is the unit of temperature in the international system of units (SI) in which, temperature is one of the seven fundamental base quantities. Temperature is important in all fields of natural science, including physics, chemistry, Earth science, medicine and biology, as well as most aspects of daily life. Here is a highlight description of temperature:
- In thermodynamics, temperature is a measure of intensity of hotness or coldness of an object.
- In thermodynamics, temperature is taken to be the average kinetic energy of molecules in a substance.
- Temperature being a measure of intensity, its standard unit of measurements is Kelvin; however, it can be measured in Celsius or Fahrenheit.
- Temperature rises when an objected is heated and falls when the object is cooled.
- Temperature is measured by a device known as thermometer.
- Temperature is represented by symbol of letter (T).
- It does not have the working ability; it is exclusively used to measure the intensity or extent of heat.
- The temperature of an object can take negative values depending on the unit system used to measure the temperature.
Also Read: Difference Between Heat And Work
Difference Between Heat And Temperature In Tabular Form
| Heat | Temperature |
|---|---|
| Heat is one form of energy. It is the thermal energy. | Temperature is not an energy. It is the thermal state of a physical body (or thermodynamic system). In classical mechanics, temperature of a body indicates the average kinetic energy of all the molecules of the corresponding body. |
| Heat flow is a reason behind temperature change. | Temperature variation can be the result of gain or loss of heat. |
| Two bodies having same temperature may not necessarily contain same quantity of heat (as heat capacities are mass dependent). | Two bodies having same heat may not necessarily have same temperature. |
| Heat is exchangeable. It can flow from one body to another. So a particular body can release or gain certain amount of heat. | Temperature is not exchangeable. Only heat can be exchanged, and the result of heat transfer can be the variation in temperature. |
| Total amount of heat present in a particular body cannot be measured. It can be measured only during flow or exchange. Thus gain or loss of heat (i.e. amount of heat flow between two bodies) can be measured. | Temperature of a particular body can be measured. Moreover, temperature does not flow (it is only heat that can flow). |
| Amount of heat transferred between two bodies can be measured by Calorimeter. | Temperature of a body can be measured by Thermometer. |
| Unit of measurement of heat is: Joule (J) in SI system or Calorie (Cal) in CGS system. | Unit of measurement of temperature is degree centigrade (°C) or Kelvin (K). |
| Its dimension is [M L2 T–2]. | Its dimension is [θ]. |
| Heat is not a fundamental property of matter. It is one derived property, and its unit is also one derived unit. | Temperature is a fundamental property of the matter. Its unit (Kelvin, K) is also a fundamental unit (or base unit). |
| Heat (similar to work) is not a property of thermodynamic system. It is a flow property. Heat capacities and specific heat capacities are, however, properties of thermodynamic system. | Temperature is one property of thermodynamic system. |
| Heat is a path function. So it relies on the path taken by a thermodynamic system to reach one state from another. | Temperature is a point function. So it is independent of the path followed by the system to reach one state from another. Every thermodynamic state has a fixed definite value of temperature. |
| The fact that whether heat will flow from one body to another body is not governed by the amount of heat present in the bodies. | It is the temperature that decides whether or not heat flow will occur between two bodies. Heat always flows from a high temperature body to a low temperature body. |
| Heat capacities (not heat) depend on the mass of the system. So these are an extensive properties. However, specific heat capacities are intensive properties. | Temperature is independent of mass; so it is an intensive property |
Summary
Heat is energy that flows between a system and its environment by virtue of temperature difference between them. It is measured by a device known as Calorimeter. Temperature on the other hand, is a measure of intensity of hotness or coldness of an object. It is measured by a device known as thermometer.