Endothermic Reaction

Chemical reactions entail the breaking and forming of chemical bonds in order to convert reactants to products. At the end of the reaction, the products obtained have properties that differ from those of the reactants; this distinguishes a chemical reaction from changes such as evaporation, in which only the form of the matter is changed.

Other chemical reactions necessitate the absorption of energy in order to proceed. Endothermic reactions are what they’re called. Endothermic reactions cannot occur on their own. Work is required in order for these reactions to occur. When endothermic reactions absorb energy, the temperature drops during the reaction. Positive heat flow (into the reaction) and an increase in enthalpy (+H) characterise endothermic reactions.

What is an Endothermic reaction?

You might think that chemical reactions only happen in laboratories, but they happen all the time in our surroundings and in our own bodies. The exchange of energy between molecules and compounds is at the heart of the majority of chemical reactions. The bonds that hold molecules together contain a lot of energy. This also implies that it takes a lot of energy to form bonds. The number of bonds broken and formed determines the total energy of a chemical reaction.

An endothermic reaction occurs when the amount of energy required to break the existing bonds in the reactants is greater than the amount of energy released when the new bonds form in the products. In other words, an endothermic reaction requires or absorbs energy in order to proceed. This required energy can be provided in a variety of ways, but it is most commonly in the form of heat. Endothermic reactions, in other words, frequently draw heat from their surroundings in order to occur.

Reaction profile of Endothermic reaction

Endothermic reactions have more energy than exothermic reactions (i.e., H>0). If H and the value of Threshold Energy are provided, the activation energy can be calculated from the given figure.

Endothermic reactions occur all around us.

Endothermic reactions that we see in our everyday lives include:

1. Photosynthesis: A classic example of an endothermic reaction is photosynthesis. Photosynthesis, as we know, is the process by which plants convert sunlight, carbon dioxide, and water into chemical energy. In this case, sunlight serves as a source of heat energy that the plants absorb and incorporate into their products.

2. Making an omelette: Have you ever wondered how the egg solidifies once it is cracked onto the pan? This is due to the egg absorbing heat energy from the pan and converting it into the delicious omelette we eat.

3. Ice Pack: When you open an instant cold pack, the components ammonium nitrate and water mix. The chemical reaction between the two causes the pack to absorb water from the environment, making it cold and ready to use on a sprained ankle.

Difference between Endothermic reaction and Exothermic reaction

• An endothermic reaction absorbs heat from the surrounding environment, whereas an exothermic reaction releases heat into the surrounding environment. 

• The endothermic reaction involves a change in positive energy, resulting in a positive enthalpy change. The exothermic reaction involves a change in negative energy, resulting in a negative enthalpy change. 

• In an endothermic reaction, more energy is used to break the bond than is released during the manufacturing process, resulting in net energy absorption.

Entropy

Entropy is a measure of a system’s overall randomness. A system with a high degree of disorder has a positive entropy value, whereas a system with a low degree of disorder has a negative value. Entropy is a thermodynamic property that describes the behaviour of a system in terms of temperature, pressure, entropy, and heat capacity.

Exothermic reactions include:

• Condensation of water vapour into rain: The condensation of water vapour into rain produces heat.

• Water Addition: When water is added to concrete, chemical reactions produce heat.

• Combustion: When something burns, no matter how small or large, it always produces an exothermic reaction.

Conclusion 

Chemical reactions entail the breaking and forming of chemical bonds in order to convert reactants to products. At the end of the reaction, the products obtained have properties that differ from those of the reactants; this distinguishes a chemical reaction from changes such as evaporation, in which only the form of the matter is changed. An endothermic reaction occurs when the amount of energy required to break the existing bonds in the reactants is greater than the amount of energy released when the new bonds form in the products. The endothermic reaction involves a change in positive energy, resulting in a positive enthalpy change. In an endothermic reaction, more energy is used to break the bond than is released during the manufacturing process, resulting in net energy absorption.