Question

Although \(\mathrm{HCl}\) and \(\mathrm{H}_{2} \mathrm{SO}_{4}\) have very different properties as pure substances, their aqueous solutions possess many common properties. List some general properties of these solutions, and explain their common behavior in terms of the species present.

Short answer

The common properties of aqueous solutions of \(\mathrm{HCl}\) and \(\mathrm{H}_2\mathrm{SO}_4\) include a sour taste, color change in indicators, reaction with metals to produce hydrogen gas, strong electrolyte behavior, and neutralization of basic solutions. These properties can be attributed to the presence and behavior of hydrogen ions (\(\mathrm{H}^{+}\)) in the solutions. The dissociation reactions of these acids in water produce \(\mathrm{H}^{+}\) ions, which are responsible for the observed chemical properties of the acid solutions.

Step-by-step solution

Identify properties of \(\mathrm{HCl}\) and \(\mathrm{H}_2\mathrm{SO}_4\) solutions

First, let's list some general properties that aqueous solutions of \(\mathrm{HCl}\) and \(\mathrm{H}_2\mathrm{SO}_4\) share: 1. Both solutions have a sour taste. 2. They can change the color of certain indicators (e.g., turn blue litmus paper red). 3. They react with metals to produce hydrogen gas. 4. Both are strong electrolytes in solution, meaning they dissolve into ions and conduct electricity. 5. They neutralize basic solutions to form salts and water.

Determine the species present in the solutions

When these acids dissolve in water, the following dissociation reactions occur: 1. For \(\mathrm{HCl}\): \(\mathrm{HCl}(\mathrm{aq}) \rightarrow \mathrm{H}^{+}(\mathrm{aq}) + \mathrm{Cl}^{-}(\mathrm{aq})\) 2. For \(\mathrm{H}_2\mathrm{SO}_4\): \(\mathrm{H}_2\mathrm{SO}_4(\mathrm{aq}) \rightarrow 2\mathrm{H}^{+}(\mathrm{aq}) + \mathrm{SO}_4^{2-}(\mathrm{aq})\) In both reactions, there is a common species produced: the hydrogen ion, \(\mathrm{H}^{+}\).

Relate the properties to the common species

Now that we know that both solutions produce a common species (\(\mathrm{H}^{+}\)), we can explain their common properties: 1. The sour taste is a characteristic of acidic solutions, which is due to the presence of hydrogen ions. 2. The color change in indicators is due to the transfer of a proton, \( \mathrm{H}^+ \), from the acid to the indicator, which changes its structure and subsequently its color. 3. When an acid reacts with a metal, hydrogen gas is produced as hydrogen ions (\(\mathrm{H}^{+}\)) are supplied by the acidic solution and combined with metal atoms to form hydrogen molecules, \(\mathrm{H}_2\mathrm{(g)}\). 4. Both solutions are strong electrolytes because the dissociation reactions of \(\mathrm{HCl}\) and \(\mathrm{H}_2\mathrm{SO}_4\) produce ions, which increase the electrical conductivity of the solution. 5. The neutralization process occurs as \(\mathrm{H}^{+}\) ions from the acidic solution react with \(\mathrm{OH}^{-}\) ions from the basic solution to form water, with the remaining ions forming salts. This common behavior is due to the presence of \(\mathrm{H}^{+}\) ions in both acid solutions. In conclusion, the common properties of \(\mathrm{HCl}\) and \(\mathrm{H}_2\mathrm{SO}_4\) solutions are attributed to the presence and behavior of hydrogen ions (\(\mathrm{H}^{+}\)) in the solutions. The chemical properties of these acid solutions are determined by the presence and interactions of \(\mathrm{H}^{+}\) ions.