A student wanted to prepare carbon (IV)oxide gas by reacting dilute sulphuric (VI)acid with barium carbonate .State and explain observation

When dilute sulfuric acid reacts with barium carbonate, you would observe:

1. Initial slight effervescence (fizzing): This is due to the production of carbon dioxide gas.
2. Formation of a white precipitate: This is barium sulfate ($\ce{BaSO4}$).
3. The effervescence quickly stops or is very minimal:

Explanation:
The reaction between dilute sulfuric acid ($\ce{H2SO4}$) and barium carbonate ($\ce{BaCO3}$) initially produces barium sulfate ($\ce{BaSO4}$), water ($\ce{H2O}$), and carbon dioxide ($\ce{CO2}$):

$$\ce{H2SO4(aq) + BaCO3(s) -> BaSO4(s) + H2O(l) + CO2(g)}$$

However, barium sulfate ($\ce{BaSO4}$) is insoluble in water. As it forms, it coats the surface of the solid barium carbonate. This insoluble layer prevents further contact between the sulfuric acid and the barium carbonate, effectively stopping the reaction and thus the production of carbon dioxide gas very quickly.