Question

A solution with a pH = 13 has approximately how many moles of OH– ions per liter?

Answer 1

Answer :

(A) The number of moles of $OH^-$ ions per liter is, 0.1 moles/L

(B) The number of molecules of $H^+$ ion is, $6.022\times 10^{10}$

(C) The pH of the solution will be, 4

Solution for part A :

First we have to calculate the pOH of the solution.

As we know that,

$pH+pOH=14\\\\13+pOH=14\\\\pOH=1$

Now we have to calculate the moles of $OH^-$ ion per liter.

$pOH=-\log [OH^-]\\\\1=-\log [OH^-]$

$[OH^-]=0.1moles/L$

Solution for part B :

First we have to calculate the $H^+$ ion concentration.

$pH=-\log [H^+]\\\\13=-\log [H^+]$

$[H^+]=10^{-13}moles/L$

Now we have to calculate the number of molecules of $H^+$ ion

As, 1 mole contains $6.022\times 10^{23}$ number of molecules of $H^+$ ion

So, $10^{-13}$ moles contains $6.022\times 10^{23}\times 10^{-13}=6.022\times 10^{10}$ number of molecules of $H^+$ ion

Solution for part C :

$pH=-\log [H^+]\\\\pH=-\log (1\times 10^{-4})$

$pH=4$

Answer 2

Answer:

Part 1--0.1

Part 2--0.0000000000001

Part 3--4

Explanation: