calculate how much strontium fluoride will dissolve in 1L of water given Ksp= 2.5x10^-9 at 25 degree celsius
To calculate how much strontium fluoride will dissolve in 1 liter (L) of water at 25 degrees Celsius, we need to use the solubility product constant (Ksp) value.
The Ksp expression for strontium fluoride (SrF2) is given as:
Ksp = [Sr2+][F^-]^2
Where [Sr2+] is the molar concentration of strontium ions (Sr2+) and [F^-] is the molar concentration of fluoride ions (F^-) in the saturated solution.
To calculate the molar concentrations of Sr2+ and F^- ions, we need to make some assumptions:
1. Assume x moles of SrF2 dissolve in 1L of water.
2. Since each SrF2 molecule dissociates into one Strontium ion (Sr2+) and two Fluoride ions (2F^-), the molar concentration of Sr2+ ions will be x moles/L, and the molar concentration of F^- ions will be 2x moles/L.
Using the stoichiometric ratios above, our Ksp expression can be rewritten as:
Ksp = (x)(2x)^2
Ksp = 4x^3
The value of Ksp for strontium fluoride is given as 2.5x10^-9. We can substitute this value into our equation and solve for x:
2.5x10^-9 = 4x^3
Rearranging the equation:
x^3 = (2.5x10^-9) / 4
x = [(2.5x10^-9) / 4]^(1/3)
x ≈ 5.82x10^-4 moles/L
Therefore, approximately 5.82x10^-4 moles of strontium fluoride will dissolve in 1L of water at 25 degrees Celsius.
To calculate how much strontium fluoride (SrF2) will dissolve in 1 liter (L) of water at 25 degrees Celsius, we need to perform the following steps:
Step 1: Write the balanced equation for the dissociation of strontium fluoride:
SrF2(s) ⇌ Sr2+(aq) + 2F^-(aq)
Step 2: Set up the expression for the solubility product constant (Ksp) using the concentration of the ions:
Ksp = [Sr2+][F^-]^2
Step 3: Since the concentration of solid (SrF2) does not change significantly, we assume it remains constant and can be ignored.
Step 4: Let's assume x moles of SrF2 dissolve in water. This would result in x moles of Sr2+ ions and 2x moles of F^- ions.
Step 5: Since the initial concentration of Sr2+ and F^- ions will be zero, we can express the equilibrium concentrations in terms of x.
Step 6: The expression for Ksp becomes:
Ksp = (x)(2x)^2 = 4x^3
Step 7: Substitute the given Ksp value into the expression:
2.5x10^-9 = 4x^3
Step 8: Solve for x by rearranging the equation and taking the cube root of both sides:
x = (2.5x10^-9 / 4)^(1/3)
Step 9: Use a calculator for the final calculation:
x ≈ 2.1x10^-4
Step 10: Remember that we assumed x moles of SrF2 dissolved in 1L of water. Therefore, the concentration of SrF2 in 1L of water would be approximately 2.1x10^-4 moles/L.