question_answer 7)

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

Answer:

When baking soda (sodium bicarbonate) is mixed with lemon juice (citric acid), a chemical change occurs. In this reaction, new substances like carbon dioxide is formed and heat is evolved. This change is irreversible. It is a chemical change. \[\begin{align} & \text{Sodium}\,\text{bicarbonate}\,\left( NaHC{{O}_{3}} \right)+\text{citric}\,\text{acid} \\ & \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\downarrow \\ & \text{Sodium}\,\text{citrate}\,+\text{carbon}\,\text{dioxide}\,+\text{water}\,+\text{heat}\uparrow \\ \end{align}\]