Question

When dilute HCl is added to a salt Q a brisk effervescence is produced
and the gas turns lime water milky. When NH4OH solution is added to
the above mixture, it produces a white precipitate which is soluble in
excess​

Answer 1

Hey mate ...though ur question is incomplete...but the answer of ur question is;

Here the salt used is any metal carbonate or metal hydrogen...the salt here is zinc carbonate. carbonate,because when acid + metal carbonate/hydrogen.. carbonate------------salt+ water + CO2 is produced.

and the gas produced is that of CO2 , which can be checked by passing lime water through..it turns it milky .

Hope it helps u mate !!

pls mark it as brainliest^_^