University Chemistry ›› 2021, Vol. 36 ›› Issue (6): 2008011.doi: 10.3866/PKU.DXHX202008011

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The pH Calculation of the Mixed Weak Acids of HA and HB Solutions

Dawei He, Haishui Wang()   

  • Received:2020-08-04 Accepted:2020-09-01 Published:2020-10-09
  • Contact: Haishui Wang


A novel approximate formula [H+]p is proposed to obtain the pH of the mixed HA and HB solutions, where[H+]HA and[H+]HB are the estimated values of[H+] for HA solution and HB solution, respectively. If cHA ≥ 2KHAand cHB ≥ 2KHB, [H+]p formula will work very well. The novel approximation formula is simple, easy to remember, and can be widely used to calculate the pH of the mixed monoprotic weak acid HA and HB solutions.

Key words: Monoprotic weak acid, Mixed solution, pH, Approximation formula