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A buffer solution used in electroplating contains 0.0300 mol of methanoic acid, HCOOH, and 0.0200 mol of sodium methanoate, HCOONa, in 1.00 dm3 of solution.
(Ka for methanoic acid = 1.78 × 10−4 mol dm−3.)
Calculate the pH of this buffer solution before any acid is added. Give your answer to 2 decimal places.
2.00 × 10−3 mol of hydrogen chloride gas is then dissolved in the buffer, with no change in volume.
Calculate the new pH of the buffer. Give your answer to 2 decimal places.