The pH of a solution is 5, when the hydroxyl ion concentration is :(a)

1.	The pH of a solution is 5, when the hydroxyl ion concentration is :(a) 10-5 mol/dm3 (b) 10-7 mol/dm3 (c) 10-9 mol/dm3 (d) 10-14 mol/dm3
Answer» Correct Option is : (C) \(10^{-9} mol/dm^3\) As we know, pH + pOH = 14 pOH = 14 - pH pOH = 14-5 pOH = 9 pOH = - log\([OH^-]\) \(pOH \implies [OH^-] = 10^{-9} mol/dm^3\) Option : (c) 10^-9mol/dm³

The pH of a solution is 5, when the hydroxyl ion concentration is :(a) 10-5 mol/dm3 (b) 10-7 mol/dm3 (c) 10-9 mol/dm3 (d) 10-14 mol/dm3

Answer»

Correct Option is : (C) \(10^{-9} mol/dm^3\)

As we know,

pH + pOH = 14

pOH = 14 - pH

pOH = 14-5

pOH = 9

pOH = - log\([OH^-]\)

\(pOH \implies [OH^-] = 10^{-9} mol/dm^3\)

Option : (c) 10^-9mol/dm³