Acids and bases may be described as strong or weak. In this section we look at the meaning of these terms as specifically applied to these compounds. The way that they can be differentiated by property is outlined.
The pH depends on the concentration of the solution. The strength of acids or bases depends on the extent to which they dissociate in aqueous solution.
Strong and weak acids and bases differ in the extent of ionization.
Strong acids and bases of equal concentrations have higher conductivities than weak acids and bases
A strong acid is a good proton donor and has a weak conjugate base.
A strong base is a good proton acceptor and has a weak conjugate acid.
Essential idea: Increased industrialization has led to greater production of nitrogen and sulfur oxides leading to acid rain, which is damaging our environment. These problems can be reduced through collaboration with national and intergovernmental organizations
Rain is naturally acidic because of dissolved CO2 and has a pH of 5.6. Acid deposition has a pH below 5.6.
Acid deposition is formed when nitrogen or sulfur oxides dissolve in water to form HNO3, HNO2, H2SO4 and H2SO3.
Sources of the oxides of sulfur and nitrogen and the effects of acid deposition should be covered.
Applications and skills
Distinction between strong and weak acids and bases in terms of the rates of their reactions with metals, metal oxides, metal hydroxides, metal hydrogen carbonates and metal carbonates and their electrical conductivities for solutions of equal concentrations.
Balancing the equations that describe the combustion of sulfur and nitrogen to their oxides and the subsequent formation of H2SO3, H2SO4, HNO2 and HNO3.
Distinction between the pre-combustion and post-combustion methods of reducing sulfur oxides emissions.
Deduction of acid deposition equations for acid deposition with reactive metals and carbonates.
In Chapter 8.4