If a buffer solution is 0.200 M in a weak acid (Ka = 1.6 x 10⁻⁵) and 0.550 M in its conjugate base, what is the pH?
a) 4.07
b) 4.25
c) 4.47
d) 4.60
a) 4.07
b) 4.25
c) 4.47
d) 4.60