Calculate the solubility product of calcium hydroxide if the solubility of Ca(OH)2(s) in water at 25◦C is 0.011 M.
Choices:
1. 1.1 × 10−5
2. 5.3 × 10−6
3. 2.7 × 10−6
4. 1.5 × 10−8
5. 1.2 × 10−4
is the answer 2)5.3....
Ca(OH)2 ==> Ca^2+ + 2OH^-
Ksp = (Ca^2+)(OH^=)^2
Set up an ICE chart, substitute into the Ksp expression and solve for Ksp.
The problem tells you that the solubility of Ca(OH)2 is 0.011M, therefore, (Ca^2+) must be 0.011M and (OH^-) must be twice that. Plug and chug.
The answer is (2) but that is 5.3E-6 and not just 5.3.
5.1×10^-6
Oh, I must be feeling a bit salty about this question. Thankfully, calcium hydroxide is anything but salty! Now, let me crunch some numbers for you.
The solubility product of calcium hydroxide can be calculated by taking the concentration of calcium ions (Ca²⁺) and hydroxide ions (OH⁻) raised to their stoichiometric coefficients (2 and 2, respectively). So, the solubility product (Ksp) is given by:
Ksp = [Ca²⁺]²[OH⁻]²
If the solubility of Ca(OH)2(s) in water at 25°C is 0.011 M, then we can say that [Ca²⁺] = 0.011 M and [OH⁻] = 0.022 M (since their stoichiometric coefficients are 2).
Plugging these values into the equation, we get:
Ksp = (0.011 M)²(0.022 M)²
= 5.972 × 10⁻⁶
So, the solubility product of calcium hydroxide is approximately 5.972 × 10⁻⁶.
Now, it's time to un-salt my mood and reveal that your answer is Option 3: 2.7 × 10⁻⁶. Party poppers for getting it right! 🎉
To calculate the solubility product (Ksp) of calcium hydroxide (Ca(OH)2), we need to use the solubility information provided and the balanced chemical equation.
The balanced chemical equation for the dissociation of calcium hydroxide in water is:
Ca(OH)2(s) → Ca2+(aq) + 2OH-(aq)
From the equation, we can see that one mole of calcium hydroxide produces one mole of calcium ions (Ca2+) and two moles of hydroxide ions (OH-).
Given that the solubility of Ca(OH)2(s) in water at 25°C is 0.011 M, we know that the concentration of Ca2+ is also 0.011 M, because one mole of Ca(OH)2 produces one mole of Ca2+.
The concentration of OH- is twice that of Ca2+, so it is 2 × 0.011 M = 0.022 M.
Now, we can calculate the solubility product (Ksp) using the equation:
Ksp = [Ca2+][OH-]^2
Substituting the known values:
Ksp = (0.011)(0.022)^2
Simplifying the equation:
Ksp = 0.000026
Therefore, the solubility product (Ksp) of calcium hydroxide is 2.6 × 10^-5.
Among the given choices, the closest option is 2.7 × 10^-6 (Choice 3).