We are given that the solubility product of platinum (II) sulfide is 9.9x10^-74
We are told to write a balanced equation for dissolving platinum (II) sulfide.
I put : PtS(S) <> Pt^2+(aq) + S^2-(aq)
and then we had to write the Ksp expression: Ksp=[Pt^2+][S2-]
The the final question says to: Calculate the volume of water required to dissolve 0.0010mg of platinum (ii) sulfide.
I do not know where to start for the problem, please help.
because i forgot to mention the solubility product given
To calculate the volume of water required to dissolve 0.0010 mg of platinum (II) sulfide, you need to use the solubility product constant (Ksp) and the molar mass of platinum (II) sulfide.
Here's how you can approach the problem step by step:
Step 1: Calculate the number of moles of platinum (II) sulfide (PtS).
To do this, you need to use the molar mass of PtS. The molar mass of PtS can be calculated as follows:
Molar mass of PtS = atomic mass of Pt + atomic mass of S = (195.08 g/mol for Pt) + (32.07 g/mol for S) = 227.15 g/mol
Now, you want to dissolve 0.0010 mg of PtS, which is equal to 0.0000010 g.
So, the number of moles of PtS can be calculated as follows:
Number of moles of PtS = mass of PtS / molar mass of PtS = (0.0000010 g) / (227.15 g/mol)
Step 2: Calculate the volume of water required to dissolve the given mass of PtS.
Since we have the number of moles of PtS, we can now use the solubility product constant (Ksp) to calculate the volume of water required.
The Ksp expression for PtS is: Ksp = [Pt^2+][S^2-]
Since the concentration of Pt^2+ and S^2- are equal in stoichiometric ratio based on the balanced equation, we can represent their concentration as x.
Using the expression for Ksp:
Ksp = x * x
Substituting the value of Ksp (9.9 x 10^-74) and solving for x:
9.9 x 10^-74 = x^2
Solving this equation will give you the concentration of Pt^2+ and S^2-, which represents x.
Step 3: Calculate the volume of water.
The volume of water would represent the volume that would contain the concentration of x. To calculate this, you need to know the volume unit you want to express the answer in.
For instance, if you want to express the volume in liters (L), you need to convert the concentration to moles per liter (mol/L) and then divide the number of moles of PtS by the concentration to get the volume.
Let's assume you want to calculate the volume of water in liters:
Volume of water (in L) = Number of moles of PtS / Concentration of PtS (in mol/L)
Substituting the calculated value of the number of moles of PtS and the concentration (x) will give you the answer in liters.
Note: Make sure to keep track of the units throughout the calculation. If you are using a different volume unit or want to express the answer in a different unit, you may need to adjust the calculation accordingly.
Why are you posting this again?
OK, I'm going to remove the duplicate below. Now you need patience until one of our chem tutors comes online.
.....PtS ==> Pt^2+ + S^2-
I....solid....0......0
C....solid....x......x
E....solid....x......s
Ksp = (Pt^2+)(S^2-)
You know Ksp, substitutethe E line into the Ksp expression and solve for x = solubility in mols/L.
Convert mols/L to grams/L with grams = mols x molar mass = ?
That give you grams PtS in 1000 mL. You want to dissolve 0.001 mg or 1E-6 grams.
1000 mL x ( 1E-6/solubility) = mL required to dissolve 0.001 mg.