Question

Write balanced equations for each of the following by inserting the correct coefficients in the blanks:

1. $\mathbf{\_Cu}{\left({\mathrm{NO}}_3\right)}_{\mathbf{2}}\left(\mathrm{aq}\right)\mathbf{+}\mathbf{\_KOH}\left(\mathrm{aq}\right)\mathbf{\to }\mathbf{\_Cu}{\left(\mathrm{OH}\right)}_{\mathbf{2}}\left(s\right)\mathbf{+}{\mathbf{\_KNO}}_{\mathbf{3}}\left(\mathrm{aq}\right)$
2. ${\mathbf{\_BCl}}_{\mathbf{3}}\left(g\right)\mathbf{+}{\mathbf{\_H}}_{\mathbf{2}}\mathbf{O}\left(l\right)\mathbf{\to }{\mathbf{\_H}}_{\mathbf{3}}{\mathbf{BO}}_{\mathbf{3}}\left(s\right)\mathbf{+}\mathbf{\_HCl}\left(g\right)$
   
3. ${\mathbf{\_CaSiO}}_{\mathbf{3}}\left(s\right)\mathbf{+}\mathbf{\_HF}\left(g\right)\mathbf{\to }{\mathbf{\_SiF}}_{\mathbf{4}}\left(g\right)\mathbf{+}{\mathbf{\_CaF}}_{\mathbf{2}}\left(s\right)\mathbf{+}{\mathbf{\_H}}_{\mathbf{2}}\mathbf{O}\left(l\right)$
   
4. $\mathit{\_}{\left(\mathrm{CN}\right)}_{\mathbf{2}}\left(g\right)\mathbf{+}\mathit{\_}{\mathbf{H}}_{\mathbf{2}}\mathbf{O}\left(l\right)\mathbf{\to }{\mathbf{\_H}}_{\mathbf{2}}{\mathbf{C}}_{\mathbf{2}}{\mathbf{O}}_{\mathbf{4}}\left(\mathrm{aq}\right)\mathbf{+}{\mathbf{\_NH}}_{\mathbf{3}}\left(g\right)$
   

Short answer

1. $\mathrm{Cu}{\left({\mathrm{NO}}_3\right)}_2\left(\mathrm{aq}\right)+2\mathrm{KOH}\left(\mathrm{aq}\right)\to \mathrm{Cu}\left({\mathrm{OH}}_2\right)\left(\mathrm{s}\right)+2{\mathrm{KNO}}_3\left(\mathrm{aq}\right)$
   
2. ${\mathrm{BCl}}_3\left(\mathrm{g}\right)+3{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\to {\mathrm{H}}_3{\mathrm{BO}}_3\left(\mathrm{s}\right)+\mathrm{HCl}\left(\mathrm{g}\right)$
   
3. ${\mathrm{CaSiO}}_3\left(\mathrm{s}\right)+6\mathrm{HF}\left(\mathrm{g}\right)\to {\mathrm{SiF}}_4\left(\mathrm{g}\right)+{\mathrm{CaF}}_2\left(\mathrm{s}\right)+3{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)$
   
4. ${\left(\mathrm{CN}\right)}_2\left(\mathrm{g}\right)+4{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\to {\mathrm{H}}_2{\mathrm{C}}_2{\mathrm{O}}_4\left(\mathrm{aq}\right)+2{\mathrm{NH}}_3\left(\mathrm{g}\right)$
   

Step-by-step solution

Step1. Considering the following chemical equations:

Balancing all atoms other than H and O, after that balanced O and H Then checked overall equation is balanced or not.

For balancing the equation we chose firstly the most complicated-looking molecule in the equation. For example H₃BO₃.

Step2. The final balanced reaction of the given reaction:

1. $\mathrm{Cu}{\left({\mathrm{NO}}_3\right)}_2\left(\mathrm{aq}\right)+2\mathrm{KOH}\left(\mathrm{aq}\right)\to \mathrm{Cu}{\left(\mathrm{OH}\right)}_2\left(\mathrm{s}\right)+2{\mathrm{KNO}}_3\left(\mathrm{aq}\right)$
   
2. ${\mathrm{BCl}}_3\left(\mathrm{g}\right)+3{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\to {\mathrm{H}}_3{\mathrm{BO}}_3\left(\mathrm{s}\right)+\mathrm{HCl}\left(\mathrm{g}\right)$
   
3. ${\mathrm{CaSiO}}_3\left(\mathrm{s}\right)+6\mathrm{HF}\left(\mathrm{g}\right)\to {\mathrm{SiF}}_4\left(\mathrm{g}\right)+{\mathrm{CaF}}_2\left(\mathrm{s}\right)+3{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)$
   
4. ${\left(\mathrm{CN}\right)}_2\left(\mathrm{g}\right)+4{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\to {\mathrm{H}}_2{\mathrm{C}}_2{\mathrm{O}}_4\left(\mathrm{aq}\right)+2{\mathrm{NH}}_3\left(\mathrm{g}\right)$