The solid X is Sodium bicarbonate (NaHCO3)
The colourless and an odourless gas Y evolved is Carbon dioxide(CO2)
When we add acetic acid to sodium bicarbonate, carbon dioxide gas is liberated. When this gas is passed through lime water, it turns milky due to the formation of a white precipitate- calcium carbonate.
The chemical reaction is
CH3COOH + NaHCO3 → CH3COONa + CO2 + H2O
Acetic Acid + Sodium bicarbonate → Sodium Acetate + Carbon dioxide + Water
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