Chapter U6.2, Problem 4E

Interpretation Introduction

Interpretation: Three examples of irreversible process which are not provided in the book are to be written.

Concept introduction: A reversible process in one that can proceed in both forward and the reverse direction. Many physical and chemical processes are reversible given the appropriate conditions. Irreversible processes are those processes that cannot be reversed.

Answer to Problem 4E

Three irreversible reactions are,

  $2\text{Mg}\text{+}{\text{O}}_2\to 2\text{MgO}$

  $\text{NaOH}\text{+}\text{HCl}\to \text{NaCl}\text{+}{\text{H}}_{\text{2}}\text{O}$

  ${\text{CaCO}}_{\text{3}}+2\text{HCl}\to {\text{CaCl}}_2+{\text{H}}_{\text{2}}\text{O}\text{+}{\text{CO}}_2$

Explanation of Solution

The reaction of magnesium and oxygen to form magnesium oxide is a irreversible reaction.

  $2\text{Mg}\text{+}{\text{O}}_2\to 2\text{MgO}$

The reaction of sodium hydroxide and hydrochloric acid to form sodium chloride and water is an example of irreversible reaction.

  $\text{NaOH}\text{+}\text{HCl}\to \text{NaCl}\text{+}{\text{H}}_{\text{2}}\text{O}$

The reaction of hydrochloric acid and calcium carbonate to form calcium chloride, water and carbon dioxide is also an example of irreversible reaction.

  ${\text{CaCO}}_{\text{3}}+2\text{HCl}\to {\text{CaCl}}_2+{\text{H}}_{\text{2}}\text{O}\text{+}{\text{CO}}_2$

Conclusion

The single arrow in a chemical reaction indicates that only forward process can occur.