Register & enjoy the perks of a Universal College Application, Easy Process, Time-saving, and Free Contact details and Brochures.
Monthly Users
Monthly Applications
Admissions
No Result Found
Home > News & Articles > Principle of Calorimetry: Definition, Formula, Principle, Types, Examples and Uses
Updated on 03rd January, 2024 , 6 min read
Calorimetry is a crucial scientific technique used to measure the heat involved in various processes, reactions, and physical changes. The term "calorimetry" is derived from the Latin word "calor," meaning heat. This technique is employed in diverse fields such as chemistry, physics, biology, and engineering, offering valuable insights into thermodynamics and energy transfer. The fundamental principle of calorimetry revolves around the conservation of energy, where the heat released or absorbed during a process is measured to understand the energy changes involved.
Just as our Universe consists of both matter and energy, matter itself is composed of various particles such as atoms and molecules. These particles exhibit constant motion, facilitated by the presence of energy. This motion occurs as a result of either collisions between particles or their back-and-forth movement. The kinetic motion of these molecules and atoms collectively gives rise to a particular form of energy known as thermal energy, or heat. Heat is omnipresent, existing in various environments, including the human body, volcanoes, and even the coldest places. It can be transferred from one object to another, and this transfer of heat can be measured through physical processes and chemical reactions. The process of measuring heat is referred to as calorimetry, which involves quantifying the change in thermal energy of an object.
Key points related to calorimetry are as follows:
In a calorimeter, two different forms of matter, preferably a liquid and a solid, are brought into contact with each other, each having distinct temperatures. As a result, heat energy is transferred from the object with a higher temperature to the one with a lower temperature.
This transfer of heat continues until a state of thermal equilibrium is reached between the two bodies. The principle of calorimetry is based on the "law of conservation of energy," which states that the total amount of heat absorbed by the colder object is equal to the total amount of heat released by the hotter object.
The fundamental concept of calorimetry can be expressed with the following formula:
Heat released by the hotter object = Heat absorbed by the colder object
To calculate the heat transfer, a formula is used:
Q = m * C * ΔT
Where:
(Fun fact: The specific heat capacity of water is approximately 4.1813 Joules per gram per Kelvin).
At the heart of calorimetry lies the calorimeter, a specialized apparatus designed to accurately measure heat changes. The calorimeter's key components include an insulated container to minimize heat exchange with the surroundings, a thermometer to monitor temperature changes, and a stirrer to ensure temperature homogeneity. The sample or substances under study are placed inside the calorimeter, and any heat transferred to or from the system can be measured with great precision.
The principle of calorimetry is rooted in the law of conservation of energy, which states that energy cannot be created or destroyed; it can only change forms or be transferred from one system to another. In a calorimetric measurement, the total heat exchanged between the system and its surroundings is measured, and according to the conservation of energy, it remains constant:
Heat Gained by the System = Heat Lost by the Surroundings
This principle allows for accurate heat measurements, as the heat released or absorbed by the system can be determined by measuring the temperature changes in the surroundings.
There are four commonly used types of calorimeters, each serving specific purposes:
Adiabatic calorimeters are employed to study runaway reactions. These calorimeters operate in an adiabatic environment, where any heat generated by the test sample causes a rise in its temperature, thus sustaining the reaction. Though the environment may not be entirely adiabatic due to some heat loss to the sample holder, a correction factor known as the phi-factor is used to adjust the calorimetric results and account for these heat losses.
Reaction calorimeters facilitate reactions within a closed, insulated container. The heat produced during the reaction is measured, and the heat content is determined by integrating heat flow over time. There are four primary types of reaction calorimeters:
Bomb calorimeters are constant-volume calorimetry used to measure the heat of combustion in a specific reaction. Electrical energy is employed to ignite the fuel, heating the surrounding air, which expands and escapes through a copper tube, leading the air out of the calorimeter. The temperature difference of the water surrounding the tube allows for the calculation of the calorie content of the fuel.
In a DSC, heat is applied to a sample contained within a small aluminum capsule or 'pan.' The heat flow into the sample is measured differentially by comparing it to the flow into an empty reference pan. DSC is commonly used for studying phase transitions and the thermal properties of materials.
To calculate the heat change (ΔH) during a process using calorimetry, the following equation is used:
ΔH = q / n
Where:
The heat change (ΔH) can be either positive or negative, indicating an endothermic or exothermic process, respectively. An endothermic process absorbs heat from the surroundings, causing the temperature inside the calorimeter to decrease. Conversely, an exothermic process releases heat into the surroundings, leading to a temperature increase.
Calorimetry finds applications in various scientific and industrial fields:
The heat transfer formula, q = mcΔt, defines the measure of heat transfer, where:
Was this Article Helpful/Relevant or did you get what you were looking for ?
👍 1,234
👎234
D Pharmacy: Admission 2024, Subjects, Colleges, Eligibility, Fees, Jobs, Salary
By - Nikita Parmar 2023-11-04 08:11:48 , 7 min readHow to Become a Pilot after 12th: In India, Courses, Exams, Fees, Salary 2023
By - Nikita Parmar 2023-08-25 09:48:44 , 11 min readThe principle of calorimetry is based on the conservation of energy, which states that energy cannot be created or destroyed, only transferred from one form to another. In calorimetry, the energy released or absorbed during a chemical or physical process is measured as heat.
Calorimetry works by measuring the heat exchanged between a system and its surroundings. A calorimeter, an insulated container, is used to trap the heat generated or absorbed during a reaction. By measuring the temperature change of the calorimeter, the heat released or absorbed by the reaction can be determined.
There are two main types of calorimetry: constant-pressure calorimetry (also known as bomb calorimetry), used for reactions at constant pressure, and constant-volume calorimetry (also known as coffee-cup calorimetry), used for reactions in open containers at constant volume.
Adiabatic calorimetry is a technique where the calorimeter is highly insulated to prevent heat exchange with the surroundings. This allows for the measurement of heat effects under adiabatic conditions.
Differential scanning calorimetry is a technique used to study the thermal behavior of materials. It measures the heat flow to or from a sample as a function of temperature or time, providing information about phase transitions, thermal stability, and reaction kinetics.
Calorimetry is used in various fields, including chemistry, biology, and material science. It is employed to study reaction enthalpies, calorific values of fuels, protein folding, heat capacity of materials, and more.
Heat capacity is the amount of heat energy required to raise the temperature of a substance by one degree Celsius. It is an essential parameter in calorimetry calculations.
The heat exchanged (q) during a process is directly proportional to the temperature change (ΔT) and the heat capacity (C) of the system: q = C * ΔT.
Calorimetry provides direct and accurate measurements of heat changes in a system. It is a versatile technique that can be applied to various chemical and physical processes.
Yes, calorimetry is widely used to determine the enthalpy change of a chemical reaction. By measuring the heat released or absorbed during the reaction, the enthalpy change (∆H) can be calculated using the formula ∆H = q / n, where "q" is the heat exchanged, and "n" is the number of moles of the reacting substance.
communication@collegesearch.in
+91 84482 99862 
Download Brochure
