The gas, liberated on adding aqueous solution of X to the substance Y, turns calcium hydroxide to calcium carbonate then find X,Y.

To solve the problem of identifying substances X and Y based on the reaction described, we need to analyze the chemical processes involved. The key points are that a gas is liberated when an aqueous solution of X is added to substance Y, and this gas is capable of turning calcium hydroxide into calcium carbonate.

Identifying the Gas

The gas that can react with calcium hydroxide (Ca(OH)₂) to form calcium carbonate (CaCO₃) is carbon dioxide (CO₂). This reaction can be represented as follows:

• Ca(OH)₂ + CO₂ → CaCO₃ + H₂O

When carbon dioxide is bubbled through a solution of calcium hydroxide, it reacts to form a white precipitate of calcium carbonate, which is often seen as a cloudy solution.

Determining Substances X and Y

Now, we need to figure out what substances X and Y could be. Since we established that the gas involved is carbon dioxide, we can deduce the following:

Substance Y

Substance Y must be a compound that can release carbon dioxide when reacted with an aqueous solution. A common example is a carbonate or bicarbonate. For instance, sodium bicarbonate (NaHCO₃) is a well-known substance that releases CO₂ when it reacts with acids:

• NaHCO₃ + HCl → NaCl + CO₂ + H₂O

Thus, Y could be sodium bicarbonate or any other carbonate compound that reacts similarly.

Substance X

Substance X, being an aqueous solution, is likely an acid that can react with the carbonate or bicarbonate to produce carbon dioxide. Common acids that could serve this purpose include:

• Hydrochloric acid (HCl)
• Acetic acid (CH₃COOH)
• Citric acid (C₆H₈O₇)

For example, if we take hydrochloric acid as X, the reaction with sodium bicarbonate (Y) would be:

• NaHCO₃ + HCl → NaCl + CO₂ + H₂O

Final Conclusion

Based on the reactions and the gas produced, we can conclude that:

• X is likely hydrochloric acid (HCl) or another acid.
• Y is likely sodium bicarbonate (NaHCO₃) or another carbonate compound.

In summary, the substances X and Y that fit the criteria of the problem are likely hydrochloric acid (X) and sodium bicarbonate (Y), as they produce carbon dioxide, which then reacts with calcium hydroxide to form calcium carbonate.