If 2.00 mL of 0.600 M NaOH are added to 1.000 L of 0.850 M CaCl2, what is the value of the reaction quotient and will precipitation occur?
I've been trying this problem over and over and haven't been able to get it. I know precipitation will not occur from my previous answer and that part was correct but not my reaction quotient.
3 answers
Why don't you post your work and let us find the error.
Ksp for Ca(OH)2 is 5.02 x 10^-8.
The way to predict whether a precipitation will occur is to calculate Qsp and compare to Ksp.
Qsp = (Ca2+)(OH-)^2. Concentration of OH- will be given by (M1V1/V2) = 0.0012
Qsp = 0.850 * (.0012)^2 = 1.22*10^-6
My homework says this is not correct...
The way to predict whether a precipitation will occur is to calculate Qsp and compare to Ksp.
Qsp = (Ca2+)(OH-)^2. Concentration of OH- will be given by (M1V1/V2) = 0.0012
Qsp = 0.850 * (.0012)^2 = 1.22*10^-6
My homework says this is not correct...
I don' see anything wrong with this. I calculated OH using 0.6 x 0.002/1.002 and came up with a slightly smaller number but it rounds to your value and if I square that and multiply by Ca (I used 0.850 x 1/1.002) = 0.848 but no matter how I slice it the answer always rounds to 1.22E-6. If the only thing you are keying in is the answer of 1.22E-6 then I think the database must be wrong. Do they want unit? Technically there are no units although I see a lot of prof using them.
1 answer