Question

Identify the product obtained and balance the following reaction.

$\mathrm{Zn}+\mathrm{HCl}\to$

Answer 1

When Zinc (Zn) react with Hydrochloric acid (HCl) , Zinc chloride(ZnCl₂ and Hydrogen(H₂) are formed.

It is an example of metal displacement reaction. Here more reactive Zinc displaces Hydrogen from Hydrochloric acid to form Zinc chloride and Hydrogen .

Following steps are used to balance the chemical equation.

i) Write the skeletal equation

$\mathrm{Zn}+\mathrm{HCl}\to {\mathrm{ZnCl}}_2+{\mathrm{H}}_2$

ii) Listing out number of atoms of various elements

$\mathrm{Zn}+\mathrm{HCl}\to {\mathrm{ZnCl}}_2+{\mathrm{H}}_2$

Atom	L.H.S	R.H.S
Zn	1	1
H	1	2
Cl	1	2

Balancing based on maximum number of atoms

iii) Balancing of Hydrogen

$\mathrm{Zn}+2\mathrm{HCl}\to {\mathrm{ZnCl}}_2+{\mathrm{H}}_2$

Number of atoms on the left hand side is equal to number of atoms on the right hand side.

So the equation is balanced.

iii) Write the physical state .

$\mathrm{Zn}\left(\mathrm{s}\right)+2\mathrm{HCl}\left(\mathrm{aq}\right)\to {\mathrm{ZnCl}}_2\left(\mathrm{s}\right)+{\mathrm{H}}_2\left(\mathrm{g}\right)$