PH of HCl solution as a function of volume.

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SUMMARY

The discussion centers on calculating the pH of a 2M HCl solution and its subsequent dilution with water. Initially, the pH is calculated as pH = -log(2), resulting in a negative value, which is valid for strong acids. For the dilution part, participants confirm that the new concentration can be expressed in terms of the volume of water added (V), and the pH can be recalculated using the formula pH = -log([HCl]). The impact of water's autoionization is acknowledged but deemed negligible for strong acid solutions.

PREREQUISITES
  • Understanding of pH calculation using the formula pH = -log[H]
  • Knowledge of strong acid behavior, specifically HCl ionization
  • Familiarity with dilution principles in chemistry
  • Basic concepts of autoionization of water
NEXT STEPS
  • Study the effects of dilution on pH for strong acids
  • Learn about the autoionization of water and its implications in acid-base chemistry
  • Explore the concept of negative pH values in strong acid solutions
  • Investigate the relationship between concentration and pH in various acid solutions
USEFUL FOR

Chemistry students, educators, and anyone interested in acid-base chemistry and pH calculations.

Bipolarity
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Homework Statement


You have a 1L of a 2M HCl solution. Assume that the HCl completely ionizes.
a) Calculate the pH of the solution right now.
b) You now add V litres of water to the solution.
Find the pH of the new dilute solution in terms of V.


Homework Equations


pH = -log[H]


The Attempt at a Solution


a) pH = -log(2) which is interestingly a negative number so I hope this is correct.
b) I'm not sure how you would do this part. Do we just find the new concentration in terms of V and then find the negative log of that? Don't we have to consider the autoionization of water?

Thanks!

BiP
 
Physics news on Phys.org
Yes, negative pH is possible.

Check the link I posted in your other thread for the way pH should be calculated. And read about dilution calculation.
 

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