Class 11 | Calorimetry (Principles Of Calorimetry))

Calorimetry (Principles Of Calorimetry) | Class - 11 | Summary Notes | By - SciWizHub | Make Study Easy |

1. PRINCIPLES OF CALORIMETRY
CLASS 11
BY - SciWizHub

2. INTRODUCTION
The Universe comprises energy and matters where matter includes particles, namely molecules and
atoms. Moreover, the molecules and atoms with the help of energy can move invariably. So, their
motion can either be that of colliding with each other or moving forward and backward.
As a result of this motion between atoms and molecules, heat energy is formed, which is one of the
fundamentals of the principles of calorimetry. Furthermore, thermal energy is present everywhere – in
the human body, in volcanoes and even in the coolest spaces. It is transferable from one body to
another body.
This heat flow that takes place within physical processes and chemical reactions is measurable.
Additionally, the procedure of measuring heat is termed calorimetry.

3. WHAT IS CALORIMETRY?
To define calorimetry, it can be said that it is an act of quantifying the change in the thermal
energy of an object. Some of the vital highlights related to calorimetry are as follows.
1)The temperature of a body or an object determines the heat amount present in that
body.
2)Temperature and heat energy are directly proportional to each other. So, this means that
the more the amount of heat energy the more is the temperature of a body.
3)To evaluate the loss and gain of thermal energy, an object’s temperature is measured
prior to and after the transfer of heat. Hence, this temperature difference ascertains the
heat change of a body.

4. EXAMPLE OF CALORIMETRY
Let us consider a hot cup of coffee or chilled ice cream, which is kept at room
temperature. Eventually, after an hour or two, the coffee will cool down, and the ice
cream will melt. This change happens because the coffee releases heat energy, and its
temperature reduces. On the other hand, the ice cream’s temperature rises as it absorbs
heat from the atmosphere.
Notably, the process of calorimetry is executed using a calorimeter. A calorimeter is a
tool that measures either the quantity of heat energy gained or released or specific heat
capacity.

5. WHAT IS THE PRINCIPLE OF CALORIMETRY
In a calorimeter, two forms of matter (desirably a liquid and a solid) are situated in
contact with one another. Moreover, both bodies have distinct temperatures. Due to
this arrangement, heat energy gets transferred from an object having a greater
temperature to an object having a lesser temperature.
However, heat flow continues until a state of thermal equilibrium is achieved between
the bodies. The principle of calorimetry signifies the “law of conservation of energy.”
Hence, this statement means that the total amount of heat absorbed by the cold object
is equal to the total amount of heat released by the hot object.

6. FORMULAS OF CALORIMETRY
The basic concept of calorimetry is as follows.
The heat released by the hot object = Heat absorbed by the cold object
The transfer of heat is evaluated with the help of a formula, which is as follows:
Q = mCΔT
Where Q = Entire heat energy (J)
m = Mass of an object or body (g)
C = Specific heat capacity (J/gm K)
ΔT = Change in temperature (°C)
(Fact: 4.1813 J/gm K is the specific heat capacity of water)