All about Heat and temperature.

Hello everyone i hope you all are fine and safe from the coronavirus outbreak. Today i am going to tell you about the heat and temperature which are two physical quantities. Hope you will be my post.

Introduction to Heat
The concept of heat in physics and chemistry is vary important as it plays a important role in our day to day life. The early concept of heat was that it is an invisible fluid which transfers from one body to the another body and this fluid was called as caloric fluid. Later the joule the famious scientist who plays important role regarding the concept of heat showed through his famious experiment that heat is actually a form of energy which can transfer from one body to another body. Later heat engines were discovered which converted heat into work.
We can define heat as a form of energy which is intransit and gives us the sensation of warmth . Heat is a physical quantity and every physical quantity has the specific unit . The SI unit of heat is joule and the CGS unit of heat is Calorie.
1joule = 4.186 calorie
Or ijoule = 4.2 calorie

Photo of heat: source

Concept of temperature

Temperature is also a physical quantity which measures the degree of hotness or coldness of a body. The concept of temperature was given by the zeroth law of thermodynamics. It is the temperature difference which decides the direction of heat flow and according to the first law of thermodynamics heat always flows from a hot body to the cold body. If the temperature of two bodies will be same there will be no heat transfer between these two bodies. The transfer of heat between two bodies will remain continuous till the temperature of these two bodies reaches at the same value. When there is no heat transfer between the system and between the two bodies this condition is known as the thermal equilibrium.

Picture of thermometer:Source

Measurement of temperature
The device used for measuring the temperature of any body is called thermometer. In thermometer we use materials such as mercury, gas , resistance, capacitance, etc whoes any property varies with temperature. You have heard about the mercury thermometer which doctors are using for measuring your body temperature. In the mercury thermometer, mercury expands with the increase in temperature . The expansion of mercury gives us direct reading of temperature in our body. Similarly in case of resistance thermometer, resistance of a conductor increases with the increase in temperature .

Picture of temperature scale:Source
Temperature scales
There are mainly four scales which are used for measuring the temperature in any body. For all the scales that measure the temperature have two fixed temperatures one is called lower and another is called upper point. The lower point of the temperature scale is the temperature of melting point of ice and the upper point is the temperature of boiling point of water.

1)Celsius scale: The Celsius scale wa firstly introduced in 1710. This scale was firstly introduced by the Andre Celsius. In this scale at the standard pressure of 1 A.T.m the melting point of ice is 0 degree Celsius and the boiling point of water is 100 degree Celsius. The whole scale is divided into hundred equal parts with each part or division measures one degree Celsius.

2)Fahrenheit scale: The Fahrenheit scale was discovered in the year of 1717. In this scale the melting point of ice is 32 degree Fahrenheit and the boiling point of water is 212 degree Fahrenheit . The whole scale is divided into the 180 equal parts or divisions . The each division of this scale measures the one degree Fahrenheit temperature.

3)Reymer scale: This scale was firstly introduced in the year of 1730 . This scale is not used too much. In this scale the melting point of ice is zero degree reymer while the boiling point of water is 80 degree raymer. The whole scale is divided into 80 equal divisions like the other scales each one division measures the one degree temperature.

4)Kelvin scale:In this scale the melting point was ice is 273 degrees of Kelvin and the boiling point of water is 373 degrees of Kelvin. Like the Celsius scale thia scale has also hundred equal divisions and each division measures the one degree of Kelvin.

Picture of graph showing latent heat and sensible heat:Source
Types of heat
Ther are mainly two types of heats that is special heat and latent heat.

1)Specific heat:It is the heat supplied to a substance that increases its temperature. When will add the heat to any substance in case of specific heat the heat is stored in the body which causes the rise in the temperature of the body . There are two important types of specific heat which are used in thermodynamics.

a) Specific heat at constant volume: specific heat at constant volume is defined as the amount of heat required to raise the temperature of unit mass of a substance through unity when the volume of the substance is constant .

b)Specific heat at constant pressure: It is defined as the amount of heat required to raise the temperature of a unit mass of a substance through unity when the pressure of remains or is put constant.

2)Latent heat: latent heat of a substance is the heat supplied to the substance that changes its state from solid to the liquid and liquid to the gas.suppose we have an cup of ice and we know that the temperature of ice is zero degree Celsius. If we are adding the heat continously to the ice its state gets changed from the ice to the water the temperature of ice remains the same zero degree that means all the heat used for only state change not for rising the temperature like sensible heat.

Resources:
1.https://courses.lumenlearning.com/cheminter/chapter/temperature-and-temperature-scales/
2.https://www.britannica.com/science/latent-heat
3.https://energyeducation.ca/encyclopedia/Sensible_heat

Thanks for reading