Expected PH for Halving Sulfate in Adirondack

The precipitation pH measured at the Woods Lake station in the Adirondack Mountains of New York fluctuated between 3.4–5.5 with a mean of 4.2 for the period extending from Mar. 1978–Dec. 1981. An analysis has been performed to identify the chemical factors causing these pH fluctuations. The pH of precipitation can be calculated from the sum of strong acid anions less the sum of base cations. The data showed that the sum of base cations increased with the sum of acid anions. However, there was only a 0.4 equivalent increase in base cations per equivalent increase in acid anions. Thus, precipitation in the Adirondacks was always acidic (pH