The pH of an aqueous solution is 4. a)The pOH of this solution ___. b)[H^+] is ___(scientific notation)=___(demical notation)   c)[OH^-] is ___ (scientific notation) d) Is this solution acidic or basic?

Expert Answers

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pH and pOH are values derived from the concentration of either [H+] or [OH-] which generally describe the acidity or basicity of the solution.  It is the -log of the concentration of H+ and OH- present in the solution. The sum of pH and pOH is equivalent to 14.

We can summarize the relationship as follows:

pH + pOH = 14
 
pH   = -log [H+]
pOH = -log [OH-]
 
For pH = 4:
 
pOH = 14 - pH
pOH  = 14 - 4
pOH = 10
 
pH    = -log [H+]
  4    = -log [H+]
[H+]  = 10^(-4)
[H+] = 1.0x10^-4 = 0.0001
 
 
pOH = -log [OH-]
 10   = -log [OH-]
[OH-] = 10^(-10)
[OH-] = 1.0x10^-10



pH > 7 basic
pH < 7 acidic
pH = 7 neutral
 
pH = 4 < 7 therefore the solution is acidic :)

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