Question

Hydroxide ion concentration of a solution is 0.001 m the poh of the solution is

Answer 1

The quantity of the amount of acid/base doesn’t determine the pH value of it.

Thus, the pH of HCl = pH of 0.0001 M of HCl.

The pH value of HCl is around 3. Thus the pOH value of HCl will be 14 - 3 = 11.

From this we can conclude that the pOH of 0.0001 M of HCl is 11.

Now, the pH and pH of a substance adds up to 14, that’s how you get the pOH.

Water undergoes auto- or self-ionization as shown in the following equation.

2H2O−−>H3O++OH−2H2O−−>H3O++OH−

An equilibrium is established between the ions produced and the unionized water. An equilibrium expression can be written for this system.

Kw=[H3O+][OH−]Kw=[H3O+][OH−]

KwKw is used to represent the equilibrium constant for the ionization of water. It is a special notation of the general representation KcKc.

The value of KwKw when measured at 25°C has been determined to be 1x10−141x10−14.

Mathematically, if one takes the log of both sides of the equation, remembering that when numbers are multiplied their logs are added, we arrive at the following equation.

log(1×10−14log(1×10−14)=log[H3O+]+log[OH−])=log[H3O+]+log[OH−]

The log(1log(1×10−14)=−14×10−14)=−14.

Thus, −14=log[H3O+]+log[OH−]−14=log[H3O+]+log[OH−]

Multiplying both sides of the equation by -1, we get

14=−log[H3O+]−log[OH−]14=−log[H3O+]−log[OH−]

The −log[H3O+]−log[H3O+] is defined as the pH, and the −log[OH−]−log[OH−] is defined as the pOH. Substituting into the equation yields the relationship between pH and pOH of a solution.

14=pH+pOH