Question

Which of the following forms of energy is released or absorbed in most chemical reactions?
(A) Light energy
(B) Electrical energy
(C) Sound energy
(D) Heat energy

Answer 1

Hint: We are looking for the most absorbed and released energy. Chemical reactions involve breaking of old bonds and formation of new bonds.

Formula used: To calculate the amount of heat released in a chemical reaction, we use the equation: $ {\text{Q = mc}}\Delta {\text{T}} $
Here, $ {\text{Q}} $ is the heat energy transferred (in joules),
 $ {\text{m}} $ is the mass of the object (in kilograms),
 $ {\text{c}} $ is the specific heat capacity of the liquid (joule per kilogram degrees Celsius),
and $ \Delta {\text{T}} $ is the change in temperature.

Complete Answer:
It is already known that exothermic reactions release heat energy from the body to the surroundings.
And, endothermic reaction absorbs heat energy from the surrounding into the body.
A chemical reaction generally involves endothermic and exothermic reactions.
Energies such as light energy, electrical energy, sound energy may or may not be accompanied with heat energy.
Therefore, we can say that heat energy is released or absorbed in most of the chemical reactions.
So, we need to see from the above options, and select the correct value.
Thus, the correct answer is option D.

Additional Information:
By the Law of Conservation of Energy, energy can neither be created nor destroyed. It keeps on transforming from one form to another. We know that the total energy of a system must remain unchanged, and that oftentimes a chemical reaction will absorb or release energy in the form of heat, light, or both. The energy change in a chemical reaction is due to the difference in the amounts of stored chemical energy between the products and the reactants. Excess energy from the reaction is released as heat and light.

Note:
The biggest example of heat energy in our solar system is the sun itself. The sun radiates heat to warm us up on the planet earth. Here, Heat transfer by radiation occurs when microwaves, infrared radiation, visible light, or another form of electromagnetic radiation is emitted or absorbed.