Question

Complete the chemical equation and balance them.

${\mathrm{BaCl}}_2+\mathrm{\_\_\_\_\_\_\_\_}\to {\mathrm{BaSO}}_4+\mathrm{NaCl}$

Answer 1

On heating barium chloride with sodium sulphate, it forms barium sulphate a white colour precipitate and sodium chloride.

${\mathrm{BaCl}}_2\left(\mathrm{aq}\right)+{\mathrm{Na}}_2{\mathrm{SO}}_4\left(\mathrm{aq}\right)\to {\mathrm{BaSO}}_4\left(\mathrm{s}\right)+\mathrm{NaCl}\left(\mathrm{aq}\right)$

Step 1:

Number of atoms in LHS, Ba = 1 atom, Cl = 2 atoms, Na = 2 atoms, S = 1 atom, O = 4 atoms

Number of atoms in RHS, Ba = 1 atom, Cl = 1 atoms, Na = 1 atom, S = 1 atom, O = 4 atoms

There is an extra atom of chlorine and sodium on the reactant side.

Step 2:

Multiply NaCl on product side by 2

${\mathrm{BaCl}}_2\left(\mathrm{aq}\right)+{\mathrm{Na}}_2{\mathrm{SO}}_4\left(\mathrm{aq}\right)\to {\mathrm{BaSO}}_4\left(\mathrm{s}\right)+2\mathrm{NaCl}\left(\mathrm{aq}\right)$

Now in LHS, we have Ba = 1 atom, Cl = 2 atoms, Na = 2 atoms, S = 1 atom, O = 4 atoms

In RHS, we have Ba = 1 atom, Cl = 2 atoms, Na = 2 atoms, S = 1 atom, O = 4 atoms

Now the number of atoms on the reactant and product side are equal and the equation is said to be balanced.

Therefore, the balanced chemical equation is ${\mathrm{BaCl}}_2\left(\mathrm{aq}\right)+{\mathrm{Na}}_2{\mathrm{SO}}_4\left(\mathrm{aq}\right)\to {\mathrm{BaSO}}_4\left(\mathrm{s}\right)+2\mathrm{NaCl}\left(\mathrm{aq}\right)$