320.0 gallons of 15 M nitric acid were added to a lake. The initial pH p the lake was 6.30 and the final pH was 4.60. What is the volume of the lake?

1 answer

Convert pH 4.60 to (H^+) = M2
gallons1 x M1 = gallons2 x M2
320 x 15 = gallons2 x 2.51E-5
Solve for gallons2
gallons 2 includes the 320 gallons that were added.