Limestone is a common rock used for road constructions. A construction company extracted 5 tons of the rock near a river on a rainy season. The rain washed away 2% of the rock into a nearby river which flows to a 10 acre and 15 feet deep lake in the area. With the help of relevant chemical equations, data, and calculations, explain how the washing of the rocks into the lake alters the pH of the lake. (Note: Your answer should include calculations of the final expected pH of the water in the lake.)