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To calculate pOH, you use the concentration of a base. Alternatively, you calculate the pH using the concentration of an acid. The question may also include a Ka or Kb value. The Ka indicates the equilibrium constant of an acid (uses concentration of hydronium ions), and the Kb indicates the equilibrium constant of a base (uses concentration of hydroxide ions).
The pOH is used when you have the concentration of OH- and is calculated the same way you would calculate pH. You can tell if you are calculating for an acid if it is giving off a proton and you are getting the H3O+ concentration. If it is a base, it would accept a proton and give you the OH- concentration.
You calculate pH and pOH by taking the negative log (-log) of [H3O+] or [OH-]. You typically calculate pH for acids and pOH for bases, but questions will often ask you for pH no matter what. Use pH+pOH=14 to convert from pOH to pH.
p before anything means to take the -Log of that thing. pH and pOH are the -log of the H concentrations and the OH concentrations. We can use the K equation to solve for the concentrations. We know we're solving for pH or pOH depending on if the reaction we are using, whether its a weak base or weak acid, and whether its Ka or Kb.
To calculate pOH it is simply =-log[OH-] , and to find pH it is -log[H+] or -log[H30+]. pOH is used to calculate the strength of bases, while pH is used to calculate the strength of acids. To find one if the other is given the equation is pH+pOH=14.
you find pOH by taking the -log[OH- concentration]. you find pH by taking the -log[H30+ concentration].When it is base you use the OH- concentration and when it is an acid you use the H30+ ion concentration. Also when the equation/problem only gives you one, you can find the other because pH + pOH=14
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