posted by Sean .
What is the total moles of ions in 500 mL of 0.120 M Ca(NO3)2?
how would i calculate this? thanks.
I haven't done chemistry for a while, but here's my best guess:
M = mol/L so 0.120 M means there is 0.12 moles of Ca(NO3)2 in a liter. The question ask for 500 mL, which is half of a litter, so I would just divide 0.12 by two and get 0.06 moles of Ca(NO3)2 in 500 mL.
Again, I'm not 100% sure, but it sounds reasonable to me of how I arrive to this answer.
OK so far but didn't go far enough.
The question is for total mols of ions.
So you have 0.12 mol/L or 0.06 mols/500 mL.
There will be 0.06 mols of Ca^+2, and 2*0.06 mols NO3^- = 0.12 mols NO3^-. The total is 0.06 + 0.12 = 0.18 mol Ca + NO3^-.