3. Determine the pH if 0.02 mol of NaOH is added to 1.0L of the buffer described in question #1.

Question

question1: 1. How many grams of NaHCO3 should be added to one liter of 0.100 M H2CO3 (Ka = 4.2 x 10-7) to prepare a buffer with pH = 7.00?

Answer 1

1st: equation: H2CO3+NaOH<-->H2O+HCO3
2ndICE For Initial: H2CO3=.100, NaOH=.02,HCO3=..42 fromquestion1
For Change:H2CO3=-.02, NaOH=-.02,HCO3=.+.02
For Equilium:H2CO3=.08, NaOH=0,HCO3=.40
2nd:Use Buffer equation: pH= -log(4.2x10-7)+log(.40÷.08)=?
3rd: answer:7pH