calculate [h3o] in solutions. 0.040 of HCl and 0.080 HOCl.
2. calculate OH for the solutions of 0.0063 ba (OH)2 and 0.0110 of BaCl2
1. This is a buffer solution. Use the Henderson-Hasselbalch equation.
2. This is made to look like a buffer solution but it isn't. Calculate OH from the Ba(OH)2 concn.
Post your work if you get stuck.
thank you. for #1, do i just get the PH and then covert that to H3O then?
but if HCL and HOCl are both strong acids, how can i use the equation? since its supposed to be an acid and base right?
No. I'm glad you asked the question because it made me look at the problem again. I gave you a bum way to go. This is not a buffered solution, it is the solution of a strong acid (HCl) and a weak acid (HOCl). What you do here is to calculate the H3O^+ from the strong acid, then the H3O^+ from the weak acid, add the moles together and divide by the volume to determine molarity. I suspect, however, that the contribution by HOCl will be very small, perhaps even negligible.
After reading your second response, HOCl is a weak acid. You can determine the Ka by looking in tables in your text or your notes.
To calculate [H3O+] in a solution, you can use the concept of acid dissociation constant (Ka) or the concentration of the acid. In the case of HCl and HOCl, both are strong acids, which means they dissociate completely in water.
1. For HCl:
Since HCl is a strong acid, it dissociates completely in water to produce H3O+ and Cl-. Therefore, the concentration of H3O+ is equal to the concentration of HCl.
[H3O+] = 0.040 M
2. For HOCl:
HOCl is a weak acid, but we can approximate the [H3O+] concentration based on its Ka value, which is 3.0 x 10^-8 at 25°C.
HOCl ↔ H+ + OCl-
Let x be the concentration of [H3O+].
Using the Ka expression:
Ka = [H+][OCl-] / [HOCl]
3.0 x 10^-8 = x * x / (0.080 - x)
Solving this quadratic equation will yield the concentration of [H3O+]. It is a bit more complex to solve without a calculator. So, you can use a mathematical software or an online quadratic equation solver to find the value. The concentration of [H3O+] will be different for each specific value of x.
To calculate [OH-] in a solution, you can use the concept of base dissociation constant (Kb) or the concentration of the base. In the case of Ba(OH)2 and BaCl2, both are strong compounds that dissociate completely in water.
1. For Ba(OH)2:
Since Ba(OH)2 is a strong base, it dissociates completely in water to produce Ba2+ and OH-. Therefore, the concentration of OH- is twice the concentration of Ba(OH)2.
[OH-] = 2 * 0.0063 M
2. For BaCl2:
BaCl2 is not a base, but we can calculate the concentration of OH- based on its contribution to the OH- concentration from the auto-ionization of water.
In water, the auto-ionization reaction is H2O ↔ H+ + OH-
The equilibrium constant for this reaction, Kw, is equal to 1.0 x 10^-14 at 25°C.
To calculate OH- concentration:
[OH-] = Kw / [H+]
In this case, we need to determine the concentration of H+ which is a result of the reaction between BaCl2 and H2O.
BaCl2 dissociates into Ba2+ and 2 Cl-. However, Cl- does not react with water, so it does not contribute to the H+ concentration.
BaCl2 + 2H2O ↔ Ba(OH)2 + 2H+ + 2Cl-
Given that [BaCl2] = 0.0110 M, the concentration of H+ is equal to the concentration of BaCl2.
[H+] = 0.0110 M
Now, we can calculate [OH-] using the equation mentioned above:
[OH-] = 1.0 x 10^-14 / [H+]
Plug in the value of [H+] to obtain the concentration of [OH-].