EK 1001 Chem
827. If 30 mL of a 3 M acetic acid (pKa = 4.7) were added to 45 mL of a 2 M sodium hydroxide, the resulting solution would have a pH:
A. less than two
B. between two and seven
C. equal to seven
D. greater than seven
Answer: D
When I did this problem, I thought it was equal to seven, since there is 90 mmol of acid and 90 mmol of base. Why is the answer D? Is it that we are supposed to recognize that acetic acid is a weak acid and so thus the NaOH "overpowers" the pH?
827. If 30 mL of a 3 M acetic acid (pKa = 4.7) were added to 45 mL of a 2 M sodium hydroxide, the resulting solution would have a pH:
A. less than two
B. between two and seven
C. equal to seven
D. greater than seven
Answer: D
When I did this problem, I thought it was equal to seven, since there is 90 mmol of acid and 90 mmol of base. Why is the answer D? Is it that we are supposed to recognize that acetic acid is a weak acid and so thus the NaOH "overpowers" the pH?