What Is The Equilibrium Constant Of Pure Water At $25^{\circ} C$?A. 10 14 10^{14} 1 0 14 B. 10 − 14 10^{-14} 1 0 − 14 C. 10 − 7 10^{-7} 1 0 − 7 D. 10 7 10^7 1 0 7

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Understanding the Equilibrium Constant

The equilibrium constant, also known as the dissociation constant, is a measure of the concentration of ions in a solution at equilibrium. It is a crucial concept in chemistry, particularly in the study of acid-base chemistry and electrochemistry. The equilibrium constant is denoted by the symbol K and is expressed as a numerical value with a unit of concentration, typically moles per liter (M).

The Equilibrium Constant of Pure Water

Pure water is a neutral solution, meaning it has a pH of 7 at 25°C. At this temperature, pure water is in equilibrium with its dissociation products, hydrogen ions (H+) and hydroxide ions (OH-). The equilibrium constant for this reaction is denoted as Kw and is expressed as:

Kw = [H+][OH-]

where [H+] and [OH-] are the concentrations of hydrogen and hydroxide ions, respectively.

Calculating the Equilibrium Constant of Pure Water

To calculate the equilibrium constant of pure water, we need to know the concentrations of hydrogen and hydroxide ions at 25°C. At this temperature, pure water is in equilibrium with its dissociation products, and the concentrations of hydrogen and hydroxide ions are equal. The concentration of hydrogen ions in pure water at 25°C is approximately 1.0 x 10^-7 M.

The Correct Answer

Using the formula Kw = [H+][OH-], we can calculate the equilibrium constant of pure water as follows:

Kw = (1.0 x 10^-7 M)(1.0 x 10^-7 M) = 1.0 x 10^-14

Therefore, the correct answer is B. 10^-14.

Understanding the Significance of the Equilibrium Constant

The equilibrium constant of pure water is an important concept in chemistry, particularly in the study of acid-base chemistry and electrochemistry. It is used to determine the pH of a solution and to predict the direction of a chemical reaction. The equilibrium constant is also used to calculate the concentration of ions in a solution at equilibrium.

Applications of the Equilibrium Constant

The equilibrium constant of pure water has several applications in chemistry and industry. It is used to:

  • Determine the pH of a solution
  • Predict the direction of a chemical reaction
  • Calculate the concentration of ions in a solution at equilibrium
  • Design and optimize chemical processes
  • Develop new materials and products

Conclusion

In conclusion, the equilibrium constant of pure water at 25°C is 10^-14. This value is an important concept in chemistry, particularly in the study of acid-base chemistry and electrochemistry. It is used to determine the pH of a solution, predict the direction of a chemical reaction, and calculate the concentration of ions in a solution at equilibrium.

Frequently Asked Questions

Q: What is the equilibrium constant of pure water at 25°C?

A: The equilibrium constant of pure water at 25°C is 10^-14.

Q: What is the significance of the equilibrium constant of pure water?

A: The equilibrium constant of pure water is an important concept in chemistry, particularly in the study of acid-base chemistry and electrochemistry. It is used to determine the pH of a solution, predict the direction of a chemical reaction, and calculate the concentration of ions in a solution at equilibrium.

Q: What are the applications of the equilibrium constant of pure water?

A: The equilibrium constant of pure water has several applications in chemistry and industry, including determining the pH of a solution, predicting the direction of a chemical reaction, calculating the concentration of ions in a solution at equilibrium, designing and optimizing chemical processes, and developing new materials and products.

References

  • Atkins, P. W., & De Paula, J. (2010). Physical chemistry (9th ed.). Oxford University Press.
  • Brown, T. E., & LeMay, H. E. (2014). Chemistry: The Central Science (14th ed.). Pearson Education.
  • Petrucci, R. H., Harwood, W. S., & Herring, F. G. (2016). General chemistry: Principles and modern applications (11th ed.). Pearson Education.

Q&A: Equilibrium Constant of Pure Water

Q: What is the equilibrium constant of pure water at 25°C?

A: The equilibrium constant of pure water at 25°C is 10^-14.

Q: What is the significance of the equilibrium constant of pure water?

A: The equilibrium constant of pure water is an important concept in chemistry, particularly in the study of acid-base chemistry and electrochemistry. It is used to determine the pH of a solution, predict the direction of a chemical reaction, and calculate the concentration of ions in a solution at equilibrium.

Q: What are the applications of the equilibrium constant of pure water?

A: The equilibrium constant of pure water has several applications in chemistry and industry, including determining the pH of a solution, predicting the direction of a chemical reaction, calculating the concentration of ions in a solution at equilibrium, designing and optimizing chemical processes, and developing new materials and products.

Q: How is the equilibrium constant of pure water calculated?

A: The equilibrium constant of pure water is calculated using the formula Kw = [H+][OH-], where [H+] and [OH-] are the concentrations of hydrogen and hydroxide ions, respectively.

Q: What is the relationship between the equilibrium constant of pure water and the pH of a solution?

A: The equilibrium constant of pure water is related to the pH of a solution through the formula pH = -log[H+]. This means that the pH of a solution is directly related to the concentration of hydrogen ions in the solution.

Q: Can the equilibrium constant of pure water be affected by temperature?

A: Yes, the equilibrium constant of pure water can be affected by temperature. As the temperature increases, the equilibrium constant of pure water also increases.

Q: What is the difference between the equilibrium constant of pure water and the equilibrium constant of an acid-base reaction?

A: The equilibrium constant of pure water is a specific value that represents the concentration of ions in pure water at equilibrium, whereas the equilibrium constant of an acid-base reaction is a value that represents the concentration of ions in a solution at equilibrium, taking into account the specific acid-base reaction.

Q: How is the equilibrium constant of pure water used in real-world applications?

A: The equilibrium constant of pure water is used in a variety of real-world applications, including:

  • Water treatment: The equilibrium constant of pure water is used to determine the pH of water and to predict the direction of chemical reactions that occur during water treatment.
  • Chemical manufacturing: The equilibrium constant of pure water is used to design and optimize chemical processes, such as the production of acids and bases.
  • Environmental monitoring: The equilibrium constant of pure water is used to monitor the pH of water and to predict the direction of chemical reactions that occur in the environment.

Q: Can the equilibrium constant of pure water be affected by the presence of impurities?

A: Yes, the equilibrium constant of pure water can be affected by the presence of impurities. Impurities can alter the concentration of ions in the solution and affect the equilibrium constant of pure water.

Q: How is the equilibrium constant of pure water measured?

A: The equilibrium constant of pure water is typically measured using techniques such as potentiometry, conductometry, and spectrophotometry.

Q: What are some common mistakes to avoid when working with the equilibrium constant of pure water?

A: Some common mistakes to avoid when working with the equilibrium constant of pure water include:

  • Failing to account for temperature effects on the equilibrium constant
  • Failing to account for the presence of impurities in the solution
  • Using incorrect values for the equilibrium constant
  • Failing to properly calibrate equipment used to measure the equilibrium constant

Conclusion

In conclusion, the equilibrium constant of pure water is an important concept in chemistry that has a wide range of applications in industry and research. Understanding the equilibrium constant of pure water is crucial for predicting the direction of chemical reactions, designing and optimizing chemical processes, and developing new materials and products.

References

  • Atkins, P. W., & De Paula, J. (2010). Physical chemistry (9th ed.). Oxford University Press.
  • Brown, T. E., & LeMay, H. E. (2014). Chemistry: The Central Science (14th ed.). Pearson Education.
  • Petrucci, R. H., Harwood, W. S., & Herring, F. G. (2016). General chemistry: Principles and modern applications (11th ed.). Pearson Education.