[student]

i have to calculate calcium moles in a 10mL hard water sample and ppm.
so i know moles of calclium would be the volume /1000Ml/L multiplied by molarity.
i have molarity of an EDTA concentration so
i multiply that which is 0.1000M x (10ml/1000) TO GET MY MOLES FOR CALCIUM
but now i have to get ppm, not sure how to get that from what i have.
And lastly, calculate total moles of Mg2+ and Ca2+ in 10ml hard water sample
because it has a ratio of 1:1
what is my total moles? how do i calculate that.
my third question is what the calculation of Mg2+ moles in hard water.
So i figure the total moles - calcium moles will give me my Mg2+

[Albert]

I'm not sure to have completely understood what you ask.

ppm = mg (mass of calcium)/ L (volume of solution)

For what concerns the rest of your question I think you should post (or outline) the text of the problem (better).

[chiralic]

Hint: Check it out on google using the keywords: water hardness conversion....and you'll get A LOT information about your post...

[student]

calculation of moles in 10ml hard water sample and ppm
so would this be right, my teacher hinted me in this direction
(0.00969L )(0.01000M) (0.001L of hard water)=9.69x10^-8

next i have to do the total moles for ca2+ and mg2+ in 10ml of hard water?
do take the average result from the total EDTA
so (0.001365L)(moles?? of ca2+ 9.69x10^-8)(0.00969 L of Ca2+)
what about the 10ml?
lost about how to do total moles.
i know the EDTA is a 1:1 ratio with the ca2+
any insight on how to actually do this.
does this look a bit better