Q100P - Chemistry: Molecular Nature Of Matter And Change

Question

Complete and balance the following: 

(a) ${\mathbf{\text{AlCl}}}_{\mathbf{\text{3}}}\mathbf{\left(}\mathbf{\text{I}}\mathbf{\right)}{\mathbf{\text{+H}}}_{\mathbf{\text{2}}}\mathbf{\text{O}}\mathbf{\left(}\mathbf{\text{I}}\mathbf{\right)}\mathbf{\to }$

(b) ${\mathbf{\text{Sb}}}_{\mathbf{\text{2}}}{\mathbf{\text{O}}}_{\mathbf{\text{3}}}\mathbf{\left(}\mathbf{\text{s}}\mathbf{\right)}\mathbf{\text{+NaOH}}\mathbf{\left(}\mathbf{\text{aq}}\mathbf{\right)}\mathbf{\to }$

Step-by-Step Solution

Answer

The answer is as follow.

(a) ${\text{AsCl}}_{\text{3}}\left(\text{l}\right){\text{+3H}}_{\text{2}}\text{O}\left(\text{l}\right)\to {\text{H}}_{\text{3}}{\text{AsO}}_{\text{3}}\left(\text{aq}\right)\text{+3HCl}\left(\text{g}\right)$

(b) ${\text{Sb}}_{\text{2}}{\text{O}}_{\text{3}}\left(\text{s}\right)\text{+6NaOH}\left(\text{aq}\right)\to {\text{2Na}}_{\text{3}}{\text{SbO}}_{\text{3}}\left(\text{aq}\right){\text{+3H}}_{\text{2}}\text{O}\left(\text{l}\right)$

Balancing of chemical equations:

Chemical reactions must have an equal amount of atoms on both sides of the chemical equation in order for the process to be balanced. This makes it easier to calculate how many moles of reactant were required to carry out the reaction and produce the relevant products.

(a) Complete and balance:

Halides of $\text{5A}$ group elements react with water to give hydrogen halides and oxoacids.

So, arsenic trichloride $\left({\text{AsCl}}_{\text{3}}\right)$ reacts with water $\left({\text{H}}_{\text{2}}\text{O}\right)$ to give hydrogen chloride $\left(\text{HCl}\right)$ and an oxoacid $\left({\text{H}}_{\text{3}}{\text{AsO}}_{\text{3}}\right)$.

Therefore, the complete equation, 

${\text{AsCl}}_{\text{3}}\left(\text{l}\right){\text{+H}}_{\text{2}}\text{O}\left(\text{l}\right)\to {\text{H}}_{\text{3}}{\text{AsO}}_{\text{3}}\left(\text{aq}\right)\text{+HCl}\left(\text{g}\right)$ 

To balance the above equation, keep the suitable coefficients on both sides (reactant and product).

Thus, the balanced chemical equation is given below.

 ${\text{AsCl}}_{\text{3}}\left(\text{l}\right){\text{+3H}}_{\text{2}}\text{O}\left(\text{l}\right)\to {\text{H}}_{\text{3}}{\text{AsO}}_{\text{3}}\left(\text{aq}\right)\text{+3HCl}\left(\text{g}\right)$

Here the product obtained is Arsenic acid.

(b) Complete and balance:

The reaction between ${\text{Sb}}_{\text{2}}{\text{O}}_{\text{3}}$ and $\text{NaOH}$ is an acid base reaction. So, salt and water are the products.  

Therefore, the complete equation is as follows:

${\text{Sb}}_{\text{2}}{\text{O}}_{\text{3}}\left(\text{s}\right)\text{+NaOH}\left(\text{aq}\right)\to {\text{Na}}_{\text{3}}{\text{SbO}}_{\text{2}}\left(\text{aq}\right){\text{+H}}_{\text{2}}\text{O}\left(\text{aq}\right)$ 

To balance the above equation, keep the suitable coefficients on both sides (reactant and product).

Therefore, the balanced chemical equation is given below.

${\text{Sb}}_{\text{2}}{\text{O}}_{\text{3}}\left(\text{s}\right)\text{+6NaOH}\left(\text{aq}\right)\to {\text{2Na}}_{\text{3}}{\text{SbO}}_{\text{3}}\left(\text{aq}\right){\text{+3H}}_{\text{2}}\text{O}\left(\text{l}\right)$ 

 

Here the product obtained is Sodium salt of Antimony oxide.