Question

Identify the product formed and balance the equation

$\mathrm{Ca}{\left(\mathrm{OH}\right)}_2+{\mathrm{H}}_2{\mathrm{CO}}_3\to$

Answer 1

When Calcium hydroxide [Ca(OH)₂] react with carbonic acid (H₂CO₃), Calcium carbonate (CaCO₃ )and water (H₂O) is formed. It is an example of neutralisation reaction

Following steps are used to balance the chemical equation.

i) Write the skeletal equation

$\mathrm{Ca}{\left(\mathrm{OH}\right)}_2+{\mathrm{H}}_2{\mathrm{CO}}_3\to {\mathrm{CaCO}}_3+{\mathrm{H}}_2\mathrm{O}$

ii) Listing out number of atoms of various elements.

Atom	L.H.S	R.H.S
Ca	1	1
O	5	4
H	4	2
C	1	1

Balancing based on maximum number of atoms

iii) Balancing of oxygen

$\mathrm{Ca}{\left(\mathrm{OH}\right)}_2+{\mathrm{H}}_2{\mathrm{CO}}_3\to {\mathrm{CaCO}}_3+2{\mathrm{H}}_2\mathrm{O}$

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 .

$\mathrm{Ca}{\left(\mathrm{OH}\right)}_2\left(\mathrm{aq}\right)+{\mathrm{H}}_2{\mathrm{CO}}_3\left(\mathrm{aq}\right)\to {\mathrm{CaCO}}_3\left(\mathrm{s}\right)+2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)$