Vero asked in Science & MathematicsChemistry · 1 decade ago

explain why solutions of salts that hydrolyze water do not have a pH of 7.?

explain why solutions of salts that hydrolyze water do not have a pH of 7.

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  • 1 decade ago
    Favorite Answer

    If you hydrolyze water you split it into it's two ions, H+ and OH-. OH- increases ph, H+ decreases pH. Whichever one is predominant determines the pH, and depending on what the salt binds to determines this.

  • Anonymous
    4 years ago

    Hydrolyze Water

  • 1 decade ago

    The anion of the salt (Ex. for K2CO3 it is CO3 2-) will react with H+ ions in water to form the molecular form of that anion's conjugate acid. (Ex. for CO3 2- it will for H2CO3). This removes some H+ ions from the solution, raising the pH above 7. This can also lower the pH. For example, in an NH4Cl solution, the NH4+ and Cl- ions will completely dissociate, and the NH4+ ions will hydrolyze with OH- ions, forming H20 and NH3, and removing OH- ions from solution, making the solution have a lower pH.

    To conclude whether a salt will make an acidic, basic, or neutral solution, examine its ions. If it contains anions of weak acids, it will be basic. If it contains cations of weak bases, it will be acidic. And if it contains anions and cations of strong acids and strong bases, then it will be neutral.

    Ex. NaF is basic because F- is the anion of a weak base. (a.k.a. HF does not ionize very much)

    Ex. (NH4)2SO4 will be acidic, because NH4+ is the cation of a weak base. (a.k.a. NH3 does not ionize very much)

    Ex. NaCl will be neutral, because Na+ and Cl- are the cations and anions of strong acids and bases (NaOH and HCl dissociate almost 100%).

  • 4 years ago

    My wager, 6 to 7. Sea water includes many compounds, sodium chloride is barely considered one of them. If u ought to stimulate sea water, elementary NaCl water probable wont do. Sea water has pH above 7, yet NaCl soln ought to have pH below 7. considering hydrochloric acid is a sturdy acid (chloride is an extremely vulnerable base) and sodium is an extremely vulnerable acid, so pH value for NaCl water devoid of contacting air ought to be 7. even if, carbon dioxide interior the air will make the soln acidic. so, 6-7 ought to be somewhat lifelike

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