Which has the highest pH: 0.1 M NaC2H3O2, 0.1 M NaCl, or 0.1 M NaNO3?


The NaC2H3O2 solution has the highest pH, and the NaCl has the lowest.
  • 0.1 M NaCl solution. The hydrolysis reaction would form HCl. HCl is a strong acid (the Ka is extremely large), so you would expect that the chloride ion would not hydrolyze at all! The pH of the solution would be close to 7.
  • 0.1 M NaC2H3O2 solution. The hydrolysis reaction would form HC2H3O2. HC2H3O2 is a weak acid (the Ka is about 1.8x10-5), so C2H3O2- would undergo hydrolysis and the pH would be greater than 7.
  • 0.1 M NaNO2 solution. The hydrolysis reaction would form HNO2. HNO2 is a weak acid (the Ka is about 7.2x10-4), so NO2- would undergo hydrolysis and the pH would be greater than 7. Since the Ka is greater than the Ka for HC2H3O2, this solution would be more weakly basic than the NaC2H3O2 solution.

Author: Fred Senese senese@antoine.frostburg.edu



General Chemistry Online! Which has the highest pH: 0.1 M NaC_2_H_3_O_2_, 0.1 M NaCl, or 0.1 M NaNO_3_?

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Last Revised 08/17/15.URL: http://antoine.frostburg.edu/chem/senese/101/acidbase/faq/print-hydrolysis-answer.shtml