[Campbell Biology P.100] According to the text, which of the following is true regarding pur... | Practice Question
According to the text, which of the following is true regarding pure water at 25°C?
A: The dissociation of water is an irreversible process, favoring the formation of H+ and OH-.
B: For every 554 million water molecules, approximately one dissociates, and the concentrations of H+ and OH- are both 10^-7 M.
C: The product of [H+] and [OH-] concentrations is 10^-7.
D: Hydrogen ions (H+) exist independently in aqueous solutions at this temperature.
Explanation
The text explicitly states: 'In pure water, only one water molecule in every 554 million is dissociated; the concentration of H+ and of OH- in pure water is therefore 10^-7 M at 25°C '. This directly supports option B.