If a solution of Ca(OH)2 has a pH of 12.31 how can I calculate the concentration of calcium hydroxide in mol L-1 ?
Write the dissociation equation:
Ca(OH)2 >>Ca+ + 2OH
So the concentration of the OH ion is twice the Ca(OH)2 .
Find the concentration of the OH ion
[H+]= antilog (-pH}
then [OH]= 1E-14/H+
Then [Ca(OH)2] = 1/2 [OH-]
note: pH +pOH = 14
Which becomes. 12.31 + pOH = 14,
POH = 14-12.31, = 1.69.
But pOH = -log[OH^-]
So 1.69=-log[OH^-]
1.69=log(1/OH)
Antilog(1.69)=1/OH
OH=1/antilog(1.69)
To calculate the concentration of calcium hydroxide, you can follow these steps:
1. Write the dissociation equation:
Ca(OH)2 >> Ca+ + 2OH-
2. Determine the concentration of the OH- (hydroxide) ion:
Since the concentration of the OH- ion is twice that of Ca(OH)2, we can calculate it using the pH value.
[H+] = antilog(-pH)
[H+] = antilog(-12.31)
[H+] = 5.26 x 10^-13 mol/L
[OH-] = 1 x 10^-14 mol/L / [H+]
[OH-] = 1 x 10^-14 mol/L / 5.26 x 10^-13 mol/L
[OH-] = 0.019 mol/L
3. Calculate the concentration of Ca(OH)2:
[Ca(OH)2] = 1/2 [OH-]
[Ca(OH)2] = 1/2 * 0.019 mol/L
[Ca(OH)2] = 0.0095 mol/L
Therefore, the concentration of calcium hydroxide in mol/L is 0.0095 mol/L.
To calculate the concentration of calcium hydroxide (Ca(OH)2) in mol L-1, you can use the dissociation equation and the pH of the solution. Here's how you can do it step by step:
1. Write the dissociation equation: Ca(OH)2 → Ca2+ + 2OH-.
This equation shows that each molecule of calcium hydroxide dissociates to form one calcium ion (Ca2+) and two hydroxide ions (OH-).
2. Determine the concentration of the hydroxide ions (OH-) in the solution.
The concentration of OH- ions is twice the concentration of Ca(OH)2, according to the dissociation equation.
3. Calculate the concentration of the hydroxide ions (OH-).
To do this, you first need to find the concentration of hydrogen ions (H+) using the pH of the solution.
- Convert the pH value to the corresponding hydrogen ion concentration using the antilog function.
[H+] = antilog(-pH)
- Since Ca(OH)2 is a strong base, the concentration of hydroxide ions (OH-) is determined by the concentration of hydrogen ions (H+) using the relationship that for a strong base, the product of [H+] and [OH-] is equal to 1E-14 at 25°C.
[OH-] = 1E-14 / [H+]
4. Calculate the concentration of calcium hydroxide (Ca(OH)2).
Since the concentration of the hydroxide ions (OH-) is twice the concentration of Ca(OH)2, you can calculate the concentration of Ca(OH)2 using the equation:
[Ca(OH)2] = 1/2 [OH-]
By following these steps, you can determine the concentration of calcium hydroxide (Ca(OH)2) in mol L-1.