Ok so a quick question. I have the equation Ca3(PO4)2 --> 3Ca+2 + 2PO4-3
Sorr its confusing, int he first part the 3 4 and too are all little numbers at the bottom, for the second part the +2 and -3 are small numbers at the top to show the charges. Ok so anyways the question says if the concentration of Ca2+ is 3.39 x 10^-7 mol/L in a saturated solution of Ca3(PO4)2 what is the concentration of PO4-3. The thing im confused about it, I don't know if that means you need to multiply the Ca concentration by three, then multiply by 2/3 to get the PO4 concentration or if the Ca concentration includes the 3 outside and then divde by 3 ND MULTIPLY by 2.
Ca3(PO4)2 ==> 3Ca^+2 + 2PO4^-3
For every x amount (in molar) of Ca3PO4 that dissolves, we will have 3X for (Ca^+2) and 2X for (PO4^-3). So you divide THE (Ca^+2) GIVEN (they didn't give you 3 times calcium, they gave calcium) by 2 to get X (which is Ca3(PO4)2 and multiply by 2 to obtain (PO4^-3). OK?
So you divide THE (Ca^+2) GIVEN (they didn't give you 3 times calcium, they gave calcium) by 2
Why 2 not 3? I'm so confused now. I divided by 3 then mulipied by 2
So sorry. I goofed. Divide Ca by 3 to get X, then multiply by 2 to obtain PO4.
Thanks very mcuh = )
You're welcome! I apologize for the confusion earlier. Let me explain the correct approach step by step.
In the equation Ca3(PO4)2 → 3Ca+2 + 2PO4-3, it shows that for every 1 molecule of Ca3(PO4)2 that dissolves, it releases 3 Ca+2 ions and 2 PO4-3 ions.
Given that the concentration of Ca+2 is 3.39 x 10^-7 mol/L in a saturated solution of Ca3(PO4)2, we want to find the concentration of PO4-3.
To do this, we need to determine the molar ratio between Ca+2 and PO4-3 in the equation. From the equation, we can see that 2 PO4-3 ions are produced for every 3 Ca+2 ions.
So, we can set up a proportion to find the concentration of PO4-3:
(3.39 x 10^-7 mol/L) / (3 Ca+2) = (x mol/L) / (2 PO4-3)
Now, rearrange the proportion to solve for x:
(x mol/L) = (2 PO4-3) * (3.39 x 10^-7 mol/L) / (3 Ca+2)
Simplifying this calculation, we divide the concentration of Ca+2 by 3, and then multiply it by 2 to obtain the concentration of PO4-3:
(x mol/L) = (2 * 3.39 x 10^-7 mol/L) / 3
Therefore, the concentration of PO4-3 would be (2 * 3.39 x 10^-7 mol/L) / 3.
I apologize for the previous incorrect explanation. I hope this clarifies the approach for finding the concentration of PO4-3 in the given saturated solution. Let me know if you have any further questions!