Question

Acid Rain and Buffers In the Midwest, the natural geologic formations are typically made of limestone (CaCO3). The limestone in the Midwest provides the lakes and soils with a natural buffer. The questions below highlight the benefits of natural buffers, or buffers in general. Pure Water 7. What is the pH of 1.000L of pure water? 8. If you add strong acid to pure water, unbuffered water, what magnitude of pH change do you expect? (pH drops a little, a lot, not at all) 9. A 200.00 mL sample of 1.000M nitric acid was added to the water sample above. What is the resulting pH?

Answer 1

7. pure water is a weakly imised so that means in pure water very concentration of hydrogen im and hydroxide ione are equal. - Ho & Ht tot [H+] - [ou] so pH of water = 7.0 the solution is neutral. & 8: Supp when we drop when a spong acid is added pure water, the concentration of H+ ions in solution increases, and pH of solution drastically Changed. so pH drops a lot. 200 mL sample 091.000 M nimic acid volume of water = 1.000L = 1000 m2 Total volume of sol = 1000ml + 200 ml = 1200 me concentration of HNO3 in water Finding Cinisial) Mivi = M₂ V₂ (Final) 1ooom x 200ml - MX 1200 mL 1.000mx Zoome = M₂ hoone 0.167 M = M2 HNO3 = 0.167 m Concentration of HNO3 1. Ht (ap) + No3 0.167 bu= -log[41] - = -loj (0167) B4 = 0.78 $ g solution is 0.78 so be changes from 7 to 0.78 a lot of change occur.