Question 614192
a logarithm is an exponent that some base must be raised to, to equal some value
___ the base for "common" logarithms is 10 (logs are common unless otherwise indicated)


when quantities are multiplied, their logs are added
___ when divided, the logs are subtracted


log(a) = b means 10^b = a



1.  log[H+] = log(1.58) + log(10^-9)


log[H+] = .199 + -9 = -8.801


pH = - log[H+] = - -8.801 = 8.8



2. - log[H+] = 3.3


log[H+] = - 3.3 = .7 - 4  (the log of the coefficient is less than one, while the exponent is an integer))


[H+] = 10^.7 * 10^-4 = 5.012 * 10^-4