Question

What is the concentration in M) of hydroxide ions in a solution at 25°C with pH 4.1537 (A) 4.15 (B) 9.85 (C) 1.42-100 (D) 7.03*10" (E) none of the above

Answer 1

Answer:

The correct answer is option 'E': None of the above.

Explanation:

Given that pH of the solution is 4.1537

From the basic relation of acids and bases we know that

$pH+pOH=14\\\\\therefore pOH=14-pH\\\\pOH=14-4.1537\\\\\therefore pOH=9.8463$

From the definition of pOH we have

$pOH=-log[OH^{-}]$

where

[OH] is the concentration of hydroxide ions in moles/Liter (M)

Applying values and subsequently solving we get

$9.8463=-log[OH^{-}]\\\\\therefore [OH^{-}]=antilog(-9.8463)\\\\\therefore [OH^{-}]=10^{-9.8463}M$

$\therefore [OH^{-}]=14.246\times 10^{-11}}M$