So in my lab book experiment i weighed and obtained 6 samples of cobalt (ii) chloride hexahydrate to create 6 different known concentration solutions of hexaaquacobalt(ii). i then used a spectrometer to get the delta max wavelengths and absorbances for the 6. then i obtained an unknown concentration solution of hexaaquacobalt(ii). i used the spectrometer to obtain the delta max wavelength and absorbance for my unknown sample and it fell within my data of the 6 known concentration solutions. i used the data (concentration and absorbance) from my 6 stock solutions to create a beer-lambert relationship graph in excel and used the slope equation to obtain my estimated molarity concentration of my unknown(absorbance was recorded at 0.686 which fell within my absorbance range of my 6 known concentration solutions and the slope equation was y=3.2474x-0.0171. i plugged in the absorbance and got an estimated 0.217 m for my unknown solution).
my question is this(sorry for all the additional info i just want to make sure i did my work right thus far): i'm going to titrate edta into my unknown solution and one of the first steps is to calculate the volume of unknown solution needed to have a titration that results in an endpoint between 15 and 25 ml.
so let's say the edta concentration is something like (.15 m) and i want the endpoint at 15.0 ml. can i use m1v1=m2v2 to calculate the volume of unknown solution needed? would my equation look like
(15.) =(.)
2.25=(.)
2.25/.217=? ml
10.3686 ml=10 ml(sig figs) of unknown solution(to get neutralized by 15 ml of edta)?
is that the correct way to do it or do i need to go about another way of doing it? i figure i can't do 15 ml of edta and make a formula to cancel units to get to ml of unknown solution because i don't even know the chemical reaction of edta+ hexaaquacobalt(ii) + sodium acetate+ hcl+ water would be in terms of products since i'm adding those all together in a flash.