Question

Match the given compounds with the gas formed, when they react with HCl.

• A. $S{O}_2$
• B. $C{O}_2$
• C. $H_{2}S$

Answer 1

$N{a}_{2}S{O}_4,CaC{O}_{3}andMgS$ are basic salts. They react with hydrochloric acid to give a salt with the evolution of a gas. In most cases, $H_{2}O$ will also be released.

$N{a}_{2}S{O}_3\left(s\right)+2HCl\left(aq\right)\to 2NaCl\left(aq\right)+S{O}_2\left(g\right)+H_{2}O\left(l\right)$

$CaC{O}_3\left(s\right)+2HCl\left(aq\right)\to CaC{l}_2\left(aq\right)+C{O}_2\left(g\right)+H_{2}O\left(l\right)$

$MgS\left(s\right)+2HCl\left(aq\right)\to MgC{l}_2\left(aq\right)+H_{2}S\left(g\right)$