Question

“The energy changes during a chemical reaction may take place in the form of heat ,light and electricity.” Meaning of the sentence

Answer 1

It means-: Energy is a property of objects which can be transferred to other objects or converted into different forms, but cannot be created or destroyed.Chemicla energy is stored within chemical compounds. A chemical compound is formed by the rearrangement of atoms that is accompanied by energy loss or gain. This energy is the chemical energy gained or lost in the formation of the compound. Food, biomass, fuel and explosives have a store of chemical energy. The energy from food is released by chemical reactions in our bodies in the form of heat. Fuels like coal, oil and natural gas contain chemical energy that may be converted into other forms of energy like heat and light. The chemical energy present in a given fuel is determined by its calorific value – the heat liberated when 1 Kg of the fuel is burnt. Batteries and explosives also contain chemical energy that could be converted into other forms of energy, like electricity.