DEAR STUDENT,
EXPLANATION: The gas 'x' is chlorine gas.when it reacts with lime water (Ca(OH)2) it forms calcium oxychloride (bleaching powder) which is used as a bleaching agent in the industry. the following reaction is involved in the process:
2 Ca(OH)2 + 2 Cl2 ⟶ Ca(OCl)2 + CaCl2 + 2 H2O
ANSWER: X is chlorine gas and 'Y' is calcium oxychloride (bleaching powder)
REGARDS,