Question

A student took solution of common salt in a test tube and added a few drops of solution X. When the kept a moist blue limus paper over the mouth of the test tube, the litmus paper turns red due to the evolution of a gas Y. X and Y repectively are
A) conc. NaOH, Cl2
B)conc. HNO3,H2
C)conc. H2SO4,HCl
D)conc. HCl,CO2.​

Answer 1

c), would be my guess because HCl is acidic and blue litmus red would be an acidic solution

Answer 2

Answer:

d) HCl, CO2

Explanation:

carbon dioxide is an acidic gas which turns blue litmus paper red easily. Moreover adding concentrated hydrochloric acid to any of the carbonates (which are common salts)