a solution saturated in calcium hydroxide(limewater) has a pH of 12.35. What is Ksp for calcium hydroxide?
How do i start this problem. please
Ca(OH)2 ==> Ca^+2 + 2OH^-
pH = 12.35
pOH = 14-12.35
Calculate (OH^-).
Convert (OH^-) to (Ca^+2)
Calculate Ksp = (Ca^+2)(OH^-)^2
Post your work if you get stuck.
I follow you so far but how do you calculate OH
pOH = 1.65 = -log(OH^-).
Do you know how to solve that?
-log(OH^-) = 1.65
log(OH^-) = -1.65
Enter -1.65 in your calculator and hit the 10x key. Tht will give you 0.022387 31M. (That is more places than you can use but that's the number that shows up on my calculator.)
To find the value of Ksp for calcium hydroxide (Ca(OH)2), we need to use the pH of the solution and the hydroxide ion concentration.
1. Start by finding the hydroxide ion concentration [OH-].
- Since the solution is saturated, we assume that Ca(OH)2 dissociates completely, giving us two OH- ions for every one Ca(OH)2 molecule. Therefore, the concentration of OH- ions is twice the concentration of Ca(OH)2.
- To find the concentration of OH- ions, we can use the formula for calculating pH: pH = -log([H+]). In this case, we need to consider the OH- concentration, so we convert the pH to [OH-].
- [OH-] = 10^(-pOH), where pOH = 14 - pH.
- Therefore, [OH-] = 10^(-pOH) = 10^-(14 - 12.35).
2. Calculate the value of [OH-] using the calculated pOH value.
3. Since Ca(OH)2 dissociates into one Ca2+ ion and two OH- ions, the concentration of Ca2+ ions is equal to [OH-]/2.
4. Now that we have the concentration of Ca2+ ions, we can use this value to calculate the Ksp (solubility product constant) for calcium hydroxide.
Ksp = [Ca2+][OH-]^2
5. Substitute the values into the equation and solve to find Ksp.