Given a solution of acetic acid. How many times of the acid concentration, acetate salt should be added to obtain a solution with pH = 7.0 [K_(a) for dissociation of CH_(3)CO OH=1.8xx10^(-5)]

Given a solution of acetic acid. How many times of the acid concentrat

1.	Given a solution of acetic acid. How many times of the acid concentration, acetate salt should be added to obtain a solution with pH = 7.0 [K_(a) for dissociation of CH_(3)CO OH=1.8xx10^(-5)]
Answer» Solution :Suppose the concentration of the acetate salt ADDED is x timesthe concentration of acetic acid solution to obtain `pH=7. "Then " [CH_(3)CO O^(-)]=x xx [CH_(3)CO OH] :.([CH_(3)CO O^(-)])/([CH_(3)CO OH])=x` Now, for acid BUFFER, `pH = pK_(a) + log .(["Salt"])/("Acid"])` `:. 7 = - log (1.8xx10^(-5))+ logxor 7 = 4.76+ log x or log x = 2.24 or x = 1.73 xx 10^(2) = 173` times