Week 3 Exercise 2: Acids And Bases Calculations

Week 3 Exercise 2 Acids And Bases Calculationscomplete The Following

Calculate the concentration in Molarity (M) when 10.0g of sodium hydroxide (NaOH) are dissolved in 250.0mL of DI water. A. What is the pH of the solution? 2) What is the pH and pOH of a 0.955M solution of nitric acid, HNO3(aq)? 3) The human blood maintains a pH of 7.40. What is the hydronium ion [H3O+] and hydroxide [OH-] concentrations of human blood? 4) How many grams of potassium hydroxide (KOH) are needed to neutralize 50.0 mL of 1.33M hydrochloric acid (HCl(aq))?

Paper For Above instruction

Acids and bases are fundamental concepts in chemistry, crucial for understanding a variety of biological, environmental, and industrial processes. This paper explores key calculations related to acids and bases, demonstrating the application of molarity, pH, pOH, and neutralization principles, with a focus on practical laboratory scenarios and physiological conditions.

Firstly, to determine the molarity of a sodium hydroxide (NaOH) solution prepared by dissolving 10.0 grams in 250.0 mL of distilled water, we need to calculate the number of moles of NaOH. The molar mass of NaOH is approximately 40.00 g/mol. Dividing 10.0 g by 40.00 g/mol yields 0.25 mol of NaOH. Since molarity (M) is defined as moles of solute per liter of solution, and here the volume is 250.0 mL or 0.250 L, the molarity is 0.25 mol / 0.250 L = 1.00 M.

Next, to find the pH of this NaOH solution, we note that NaOH is a strong base and dissociates completely in water. The hydroxide ion concentration [OH-] is therefore equal to the molarity of the solution, which is 1.00 M. The pOH is calculated as -log[OH-], giving pOH = -log(1.00) = 0.00. The pH is related to pOH by the equation pH + pOH = 14.00; thus, pH = 14.00 - 0.00 = 14.00, indicating a highly basic solution.

In the next calculation, evaluating the pH and pOH of a 0.955 M nitric acid (HNO3) solution involves recognizing that nitric acid is a strong acid and dissociates completely. Therefore, [H3O+] = 0.955 M. The pH is calculated as -log[H3O+], which equals approximately -log(0.955) ≈ 0.02. Correspondingly, pOH = 14.00 - pH ≈ 13.98, demonstrating the strongly acidic nature of the solution.

The physiological context presents another interesting calculation: blood maintains a pH of approximately 7.40, essential for homeostasis. To determine the [H3O+] concentration, we use the formula: [H3O+] = 10^-pH. Substituting, [H3O+] = 10^-7.40 ≈ 3.98 x 10^-8 M. The [OH-] concentration is derived from the ion product of water, Kw = 1.0 x 10^-14, such that [OH-] = Kw / [H3O+], resulting in approximately 2.51 x 10^-7 M. These concentrations are tightly regulated within the human body to prevent acidosis or alkalosis, both of which can have severe health implications.

Finally, calculating the amount of KOH needed to neutralize a given HCl solution employs the principle of acid-base neutralization. The balanced chemical reaction is KOH + HCl → KCl + H2O. Given the concentration and volume of HCl, the moles of HCl are 1.33 mol/L x 0.050 L = 0.0665 mol. Since the molar ratio of KOH to HCl is 1:1, the same number of moles of KOH is required. The molar mass of KOH is approximately 56.11 g/mol, so the mass needed is 0.0665 mol x 56.11 g/mol ≈ 3.73 g. This calculation is critical in pharmaceutical and industrial processes where precise neutralization is necessary for safety and efficacy.

In conclusion, these calculations exemplify fundamental principles of acid-base chemistry, including molarity, pH, pOH, and neutralization. Mastery of these concepts enables accurate laboratory measurements and deepens understanding of biological systems such as blood pH regulation. Proper application of these principles ensures safe chemical handling and effective treatment of health conditions related to pH imbalances.

References

  • Brown, T. L., LeMay, H. E., Bursten, B. E., & Murphy, C. (2014). Chemistry: The Central Science (13th ed.). Pearson.
  • Petrucci, R. H., Herring, F. G., Madura, J. D., & Bissonnette, C. (2017). General Chemistry: Principles & Modern Applications (11th ed.). Pearson.
  • Chang, R., & Goldsby, K. (2016). Chemistry (12th ed.). McGraw-Hill Education.
  • Atkins, P., & de Paula, J. (2014). Physical Chemistry (10th ed.). Oxford University Press.
  • Zumdahl, S. S., & Zumdahl, S. A. (2019). Chemistry: An Atoms First Approach (2nd ed.). Cengage Learning.
  • Millipore Sigma. (2020). pH and pOH calculations. Retrieved from https://www.sigmaaldrich.com
  • National Institute of Health. (2022). Blood pH and Homeostasis. NIH Publications.
  • International Union of Pure and Applied Chemistry (IUPAC). (2019). Standard definitions and recommendations for molarity calculations.
  • Lewis, D. W., & Pilling, M. J. (2014). Acid-base reactions and their biological significance. Journal of Chemical Education.
  • American Chemical Society. (2021). Safety guidelines for handling acids and bases in laboratory settings.

Related Assignments