So i'm generally good with Molarity problems but on a few they threw mg/ml into the mix and its throwing me off. I think i did these right but could someone check them?
The first problem is, you weigh out exactly 0.250g of CaCo3 (form. weight= 100.09g/mol) and disolve it in exactly 250 ml of water. Calculate the Ca concentration in mg/ml AND M.
So for mg/ml I did. 0.250g * 1000mg / 250ml = 1.00 mg/ml
For M I did 0.250 g CaCo3 / 100.09 g/mol / 0.250 L H20 = 9.91x10^-3 M
The second problem is you are titrating 25.00 ml of a 1.00 mg/ml CaCo3 solution, how many ml of 0.010 M EDTA solution will be needed to reach the endpoint.
So I did: 25.00 ml * 1mg/ml = 25mg CaCo3
* 1g/100mg = 0.025g CaCo3
/100.09 g/mol= 2.49x10^-4 mol of CaCo3
/0.010 M EDTA = 0.02497 mL
Rounded to two sig figs = 0.025 mL
Am I anywhere close to being right? Thanks so much! It's been two semesters since I had Intro to Chem lecture and it's making taking the labs now much more difficult