Question

When baking soda is mixed with lemon, bubbles are formed with the evolution of a gas. What type of change is it? Explain.

Answer 1

Hint: There are two types of changes reversible and irreversible changes. Reversible changes can be undone but on contrary we cannot undo irreversible changes. In this question the evolution cannot be undone and chemicals are also involved in this.

Complete-step- by- step answer:
The reaction between baking soda and lemon juice can be given as below:
\[lemon\text{ }juice+baking\text{ }soda\xrightarrow{{}}C{{O}_{2}}(bubbles)+other\text{ }substances\]

When bicarbonate of soda is mixed with juice then it’s a chemical process, bubbles are formed with the evolution of a $C{{O}_{2}}$ gas.
Since a chemical reaction is taking place which can't be reversed, it is a chemical change.

A chemical change occurs when a substance combines with another to make a completely different substance, which is a replacement of the two and is called chemical synthesis or otherwise chemical decomposition of a substance into two or more different substances. These processes are called chemical reactions and, generally, aren't reversible except by further chemical reactions. Some reactions which produce heat as a by-product are called exothermic reactions. Some reactions require heat, as it enables them to occur and are called endothermic reactions. Understanding chemical changes may be a major part of the science of chemistry.

When chemical reactions occur, the atoms are rearranged and therefore the reaction is amid an energy change as new products are generated. An example of a chemical process is that the reaction between sodium and water to supply caustic soda and hydrogen. So much energy is released that the hydrogen gas released spontaneously burns within the air. This is an example of a chemical process because the top products are chemically different from the substances before the reaction.

Note: There are two changes one is reversible and the other is irreversible in nature.
In a chemical reaction the reactants react with each other to form a product and we cannot convert this product back into its initial form as the reactants.