When the aqueous reaction between Sn2+(aq) and MnO4−(aq) is carried out at pH 1, balancing the chemical equation requires inserting H2O molecules rather than OH− ions. Which of the following statements best explains this requirement?
a) OH− would neutralize the acidic medium (pH 1), altering the reaction conditions, so H2O is used instead.
b) The high concentration of H+ in the medium enables H2O to supply oxygen atoms while maintaining charge neutrality.
c) In acidic solutions the balancing procedure actually calls for OH− to remove excess H+, but because the pH is already so low only H2O is added.
d) OH− would precipitate manganese as Mn(OH)2, so it cannot appear in the balanced equation.