Chapter 8, Problem 31A

Interpretation Introduction

Interpretation:The two examples of each type of reaction given below needs to be given.

• Acid-base reaction
• Reaction which forms gaseous product

Concept Introduction:A chemical reaction can be describe as the process of conversion of reactant molecules to product molecules by breaking and making of chemical bonds.

On the basis of formation of products, chemical reactions can be classified in various types such as precipitation reaction, decomposition reaction, acid-base reaction, synthesis reaction, combustion reaction, etc.

Answer to Problem 31A

Acid-base reaction:

  ${\text{NaOH + HNO}}_{\text{3}}{{}_{\text{(aq}}}_{\text{)}}\stackrel{}{\to }{\text{ NaNO}}_{\text{3}}{{}_{\text{(aq}}}_{\text{)}}{\text{ + H}}_{\text{2}}{\text{O}}_{\text{(l)}}$

  ${\text{2 KOH}}_{\text{(aq)}}{\text{ + H}}_{\text{2}}{\text{SO}}_{\text{4(aq}}{}_{\text{)}}\stackrel{}{\to }{\text{ K}}_{\text{2}}{\text{SO}}_{\text{4(aq}}{}_{\text{)}}{\text{ + 2 H}}_{\text{2}}{\text{O}}_{\text{(l)}}$

Combustion reaction:

  ${\text{2 C}}_2{\text{H}}_6{}_{\text{(g)}}{\text{ + 7 O}}_{\text{2}}{}_{\text{(s) }}\stackrel{}{\to }{\text{ 4 CO}}_{\text{2}}{}_{\text{(g)}}+6{\text{H}}_{\text{2}}{\text{O}}_{\text{(g)}}$

  ${\text{C}}_{\text{2}}{\text{H}}_{\text{5}}{\text{OH}}_{\text{(l)}}{\text{ + 3 O}}_{\text{2}}{}_{\text{(s) }}\stackrel{}{\to }{\text{ 2 CO}}_{\text{2}}{}_{\text{(g)}}+3{\text{H}}_{\text{2}}{\text{O}}_{\text{(g)}}$

Explanation of Solution

Acids are the substances which tend to give ${\text{H}}^{\text{+}}$ ions in their solution whereas bases give ${\text{OH}}^{\text{-}}$ ions. The acid-base reaction is the reaction of acid and base to form salt and water. Two examples of acid-base reactions are as given below:

  ${\text{NaOH + HNO}}_{\text{3}}{{}_{\text{(aq}}}_{\text{)}}\stackrel{}{\to }{\text{ NaNO}}_{\text{3}}{{}_{\text{(aq}}}_{\text{)}}{\text{ + H}}_{\text{2}}{\text{O}}_{\text{(l)}}$

  ${\text{2 KOH}}_{\text{(aq)}}{\text{ + H}}_{\text{2}}{\text{SO}}_{\text{4(aq}}{}_{\text{)}}\stackrel{}{\to }{\text{ K}}_{\text{2}}{\text{SO}}_{\text{4(aq}}{}_{\text{)}}{\text{ + 2 H}}_{\text{2}}{\text{O}}_{\text{(l)}}$

Combustion reactions are the chemical reactions which occur in the presence of excess of oxygen to form carbon dioxide and water vapour as the final product. Two examples of combustion reaction are as given below:

  ${\text{2 C}}_2{\text{H}}_6{}_{\text{(g)}}{\text{ + 7 O}}_{\text{2}}{}_{\text{(s) }}\stackrel{}{\to }{\text{ 4 CO}}_{\text{2}}{}_{\text{(g)}}+6{\text{H}}_{\text{2}}{\text{O}}_{\text{(g)}}$

  ${\text{C}}_{\text{2}}{\text{H}}_{\text{5}}{\text{OH}}_{\text{(l)}}{\text{ + 3 O}}_{\text{2}}{}_{\text{(s) }}\stackrel{}{\to }{\text{ 2 CO}}_{\text{2}}{}_{\text{(g)}}+3{\text{H}}_{\text{2}}{\text{O}}_{\text{(g)}}$

Conclusion

Combustion reaction forms gaseous product whereas acid-base reactions forms salt and water.