A Solution Of $NaOH (aq)$ Contains $6.2 \, \text{g} \, NaOH (s)$ Per \$100.0 \, \text{mL}$[/tex\] Of Solution. Calculate The PH And The POH Of The Solution At $25^{\circ} C$.

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Introduction

Sodium hydroxide (NaOH) is a strong base commonly used in various industrial and laboratory applications. In this article, we will discuss the calculation of pH and pOH of a solution containing NaOH. The given solution contains 6.2 g of NaOH per 100.0 mL of solution at 25°C.

Understanding the Properties of NaOH

NaOH is a strong base that completely dissociates in water to produce sodium ions (Na+) and hydroxide ions (OH-). The dissociation reaction is as follows:

NaOH (aq) → Na+ (aq) + OH- (aq)

Calculating the Concentration of NaOH

To calculate the pH and pOH of the solution, we need to determine the concentration of NaOH. The given mass of NaOH is 6.2 g, and the volume of the solution is 100.0 mL. We can calculate the molarity of NaOH using the following formula:

Molarity (M) = (mass of NaOH in g) / (molar mass of NaOH × volume of solution in L)

The molar mass of NaOH is 40 g/mol. Therefore, the molarity of NaOH is:

M = (6.2 g) / (40 g/mol × 0.1 L) = 1.55 M

Calculating the Concentration of OH-

Since NaOH is a strong base, it completely dissociates in water to produce OH- ions. Therefore, the concentration of OH- ions is equal to the concentration of NaOH, which is 1.55 M.

Calculating pOH

The pOH of a solution is the negative logarithm of the concentration of OH- ions. We can calculate pOH using the following formula:

pOH = -log[OH-]

where [OH-] is the concentration of OH- ions in M.

pOH = -log(1.55) = 0.20

Calculating pH

The pH of a solution is the negative logarithm of the concentration of H+ ions. Since NaOH is a strong base, it completely dissociates in water to produce OH- ions, which in turn react with H+ ions to form water. Therefore, the concentration of H+ ions is very low, and we can assume that the pH of the solution is equal to the pOH.

pH = pOH = 0.20

Conclusion

In this article, we calculated the pH and pOH of a solution containing 6.2 g of NaOH per 100.0 mL of solution at 25°C. The concentration of NaOH was calculated to be 1.55 M, and the concentration of OH- ions was found to be equal to the concentration of NaOH. The pOH of the solution was calculated to be 0.20, and the pH of the solution was found to be equal to the pOH.

References

  • "Sodium Hydroxide" by Wikipedia, retrieved on February 25, 2024.
  • "Strong Bases" by Chemistry LibreTexts, retrieved on February 25, 2024.

Discussion

The calculation of pH and pOH of a solution containing NaOH is an important aspect of chemistry. Understanding the properties of strong bases like NaOH is crucial in various industrial and laboratory applications. The calculation of pH and pOH can be used to determine the concentration of NaOH in a solution, which is essential in various chemical reactions.

Related Topics

  • Strong Acids and Bases
  • pH and pOH Calculations
  • Chemical Reactions and Equations

Further Reading

  • "Acid-Base Chemistry" by Chemistry LibreTexts, retrieved on February 25, 2024.
  • "pH and pOH Calculations" by Chemistry LibreTexts, retrieved on February 25, 2024.

Note: The content of this article is for educational purposes only and should not be used for any commercial or industrial applications without proper consultation and validation.

Introduction

In our previous article, we discussed the calculation of pH and pOH of a solution containing sodium hydroxide (NaOH). In this article, we will address some frequently asked questions (FAQs) related to the calculation of pH and pOH of a solution containing NaOH.

Q&A

Q1: What is the difference between pH and pOH?

A1: pH and pOH are two related but distinct concepts in chemistry. pH is the negative logarithm of the concentration of hydrogen ions (H+) in a solution, while pOH is the negative logarithm of the concentration of hydroxide ions (OH-) in a solution.

Q2: How do I calculate the pH of a solution containing NaOH?

A2: To calculate the pH of a solution containing NaOH, you need to determine the concentration of NaOH in the solution. Once you have the concentration of NaOH, you can calculate the concentration of OH- ions, which is equal to the concentration of NaOH. Then, you can calculate the pOH using the formula pOH = -log[OH-]. Finally, you can calculate the pH using the formula pH = 14 - pOH.

Q3: What is the relationship between pH and pOH?

A3: The pH and pOH of a solution are related by the following equation: pH + pOH = 14. This equation is known as the acid-base dissociation constant (Ka) equation.

Q4: How do I determine the concentration of NaOH in a solution?

A4: To determine the concentration of NaOH in a solution, you need to know the mass of NaOH in the solution and the volume of the solution. You can calculate the molarity of NaOH using the following formula: M = (mass of NaOH in g) / (molar mass of NaOH × volume of solution in L).

Q5: What is the effect of temperature on the pH and pOH of a solution?

A5: The pH and pOH of a solution are affected by temperature. As the temperature increases, the pH and pOH of a solution decrease. This is because the dissociation of water into H+ and OH- ions increases with temperature.

Q6: Can I use pH and pOH to determine the concentration of NaOH in a solution?

A6: Yes, you can use pH and pOH to determine the concentration of NaOH in a solution. By knowing the pH and pOH of a solution, you can calculate the concentration of NaOH using the following equation: [NaOH] = 10^(-pOH) - 10^(-pH).

Q7: What are some common applications of pH and pOH calculations?

A7: pH and pOH calculations have many common applications in chemistry, including the determination of the concentration of strong bases like NaOH, the calculation of the pH of a solution, and the determination of the acid-base properties of a solution.

Conclusion

In this article, we addressed some frequently asked questions (FAQs) related to the calculation of pH and pOH of a solution containing sodium hydroxide (NaOH). We hope that this article has provided you with a better understanding of the concepts of pH and pOH and how to calculate them.

References

  • "Sodium Hydroxide" by Wikipedia, retrieved on February 25, 2024.
  • "Strong Bases" by Chemistry LibreTexts, retrieved on February 25, 2024.
  • "pH and pOH Calculations" by Chemistry LibreTexts, retrieved on February 25, 2024.

Discussion

The calculation of pH and pOH of a solution containing NaOH is an important aspect of chemistry. Understanding the properties of strong bases like NaOH is crucial in various industrial and laboratory applications. The calculation of pH and pOH can be used to determine the concentration of NaOH in a solution, which is essential in various chemical reactions.

Related Topics

  • Strong Acids and Bases
  • pH and pOH Calculations
  • Chemical Reactions and Equations

Further Reading

  • "Acid-Base Chemistry" by Chemistry LibreTexts, retrieved on February 25, 2024.
  • "pH and pOH Calculations" by Chemistry LibreTexts, retrieved on February 25, 2024.