For each strong acid solution, determine [H₃O⁺], [OH^–], and pH. d. a solution that is 0.655% HNO₃ by mass (assume a density of 1.01 g/mL for the solution)

Verified step by step guidance

1. Convert the percentage concentration of HNO₃ to a molarity. Start by assuming you have 100 g of the solution, which means you have 0.655 g of HNO₃.
2. Calculate the number of moles of HNO₃ using its molar mass (63.01 g/mol).
3. Determine the volume of the solution in liters using the given density (1.01 g/mL).
4. Calculate the molarity of the HNO₃ solution by dividing the moles of HNO₃ by the volume of the solution in liters.
5. Since HNO₃ is a strong acid, it dissociates completely in water. Therefore, [H₃O⁺] is equal to the molarity of the HNO₃ solution. Use this to find [OH⁻] using the water dissociation constant (K_w = 1.0 x 10⁻¹⁴) and calculate the pH using the formula pH = -log[H₃O⁺].

Key Concepts

Strong Acids and Ionization

Strong acids, like HNO3, completely dissociate in water, meaning that all the acid molecules break apart into ions. For HNO3, this results in a concentration of hydronium ions [H3O+] equal to the concentration of the acid. Understanding this complete ionization is crucial for calculating the concentrations of [H3O+] and [OH-] in the solution.

pH Calculation

The pH of a solution is a measure of its acidity, defined as the negative logarithm of the hydronium ion concentration: pH = -log[H3O+]. For strong acids, where [H3O+] can be directly determined from the acid concentration, calculating pH becomes straightforward. This concept is essential for determining the acidity of the solution in question.

Concentration and Density

To find the molarity of the HNO3 solution, we need to convert the mass percentage to moles per liter using the solution's density. The mass percentage indicates how many grams of solute are present in a certain mass of solution, and the density allows us to convert this mass into volume. This step is critical for accurately determining the concentrations of [H3O+] and [OH-].