Question

What is the effect of $HCl$ on following?
(a) $Mg$ ribbon
(b) $NaOH$
(c) crushed eggshell

Answer 1

To solve this question, we need to know that when $HCl$ will react with the given compounds or elements then the chlorine of it will get attached to the metal and will try to make metal chlorides.

Complete step by step answer:
As in question, metals are present in all given compounds. So, when these metals, metal hydroxide or metal carbonate, react with $HCl$ then they form metal chlorides and the chlorine of hydrogen chloride gets replaced by that metal. Hydrogen chloride is also known as hydrochloric acid.
(a). For $Mg$ ribbon, when magnesium ribbon reacts with hydrogen chloride the magnesium reacts with chlorine of hydrogen chloride and magnesium chloride is obtained with the release of hydrogen gas. This reaction can be shown as:
$2HCl + Mg \to MgC{l_2} + {H_2}$
(b). For $NaOH$ that is sodium hydroxide,
When sodium hydroxide reacts with hydrogen chloride then sodium of sodium hydroxide reacts with chlorine of hydrogen chloride and sodium chloride is obtained with the release of water. This reaction can be shown as:
$2HCl + NaOH \to NaCl + {H_2}O$
(c). For crushed eggshell,
The crushed eggshell is the other name for calcium carbonate. It has the chemical formula $CaC{O_3}$.
When calcium carbonate reacts with hydrogen chloride then calcium of calcium carbonate reacts with chlorine of hydrogen chloride and calcium chloride is obtained with the release of carbon dioxide and water. This reaction can be shown as:
$2HCl + CaC{O_3} \to CaC{l_2} + C{O_2} + {H_2}O$

Note:
We need to remember that if a metal has a valency of one then in its metal chloride only one chlorine will be there and if a metal has a valency of two then its metal chloride will have two chlorides in it.