Calculate the pH of a 0.10 M HNO3 solution and a 5.0 × 10^-2 M NaOH solution.

• A. pH of HNO3 is 2.0; pH of NaOH is 12.7
• B. pH of HNO3 is 1.0; pH of NaOH is 13.7
• C. pH of HNO3 is 2.0; pH of NaOH is 13.0
• D. pH of HNO3 is 1.0; pH of NaOH is 12.7

Answer: (D)

Verified step by step guidance

1. Identify the nature of the solutions: HNO3 is a strong acid and NaOH is a strong base. This means they completely dissociate in water.
2. For the HNO3 solution, use the formula for pH: \( \text{pH} = -\log[\text{H}^+] \). Since HNO3 is a strong acid, the concentration of \( \text{H}^+ \) ions is equal to the concentration of the acid, which is 0.10 M.
3. Calculate the pH of the HNO3 solution by substituting the concentration into the pH formula: \( \text{pH} = -\log(0.10) \).
4. For the NaOH solution, use the formula for pOH: \( \text{pOH} = -\log[\text{OH}^-] \). Since NaOH is a strong base, the concentration of \( \text{OH}^- \) ions is equal to the concentration of the base, which is 5.0 \times 10^{-2} \text{ M}.
5. Calculate the pOH of the NaOH solution by substituting the concentration into the pOH formula: \( \text{pOH} = -\log(5.0 \times 10^{-2}) \). Then, use the relationship \( \text{pH} + \text{pOH} = 14 \) to find the pH of the NaOH solution.