Moderate

A certain buffer solution contains equal concentration of salt and acid. ,The Ka for salt is 10-10. The pH of the buffer is:

Correct answer: B. 10

  • A. 6
  • B. 10
  • C. 4
  • D. 14

Explanation

Option B is correct.Yes, a buffer solution that contains equal concentrations of salt and acid will have a pH that is equal to the pKa of the acid. The pKa of an acid is the pH at which the acid is 50% dissociated. In other words, at the pKa, the concentration of the acid and its conjugate base are equal. In the buffer solution that you described, the salt is the conjugate base of the acid. Because the concentrations of the salt and acid are equal, the pH of the buffer will be equal to the pKa of the acid. In this case, the pKa of the acid is 10. This means that the pH of the buffer will also be 10.

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About Chemical Equilibrium

Reversible reactions reach dynamic equilibrium when forward and reverse rates become equal, and Le Chatelier's principle predicts the effect of changing concentration, pressure or temperature. The chapter also covers solubility product, the common ion effect, buffer action and the conditions used in Haber's process, with equilibrium shifts distinguished from changes in the equilibrium constant.

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