pK_{a}s . K_{a} for benzoic acid is 6.5 \times 10^{-5}. What is the pK_{a} of this acid?
Strategy : The pK_{a} is -log K_{a} . Thus, use your calculator to find the log of the K_{a} and then take the negative of it.
pK_{a}s . K_{a} for benzoic acid is 6.5 \times 10^{-5}. What is the pK_{a} of this acid?
Strategy : The pK_{a} is -log K_{a} . Thus, use your calculator to find the log of the K_{a} and then take the negative of it.
Take the logarithm of 6.5 \times 10^{-5} on your scientific calculator. The answer is -4.19. Because pK_{a} is equal to -log K_{a} , you must multiply this value by -1 to get pK_{a} . The pK_{a} of benzoic acid is 4.19.