# Chem hwk

posted by on .

How many grams of solute are required to make a 504 mL solution of copper (I) nitrate with a concentration of 1.3317 M?

I go 238.6 g but my friend said I'm way off

When 84.2730 grams of solute are used to make a 504 mL solution of copper (I) nitrate, what is the concentration of the solution?

i don't know how this is done...

• Chem hwk - ,

mols needed = M x L = 13317*0.504 = ?
Then mol = grams/molar mass so
?mols x molar mass Ci(NO3)2 = ? and I get something like 126 grams or so.

Convert g Cu(NO3)2 to mols. mols = grams/molar mass
Then M = mols/L soln.

• Chem hwk - ,

neither of these answers worked in my homework submission. Even though I already submitted can you see where either answer may be incorrect?

• Chem hwk - ,

Yes, if you posted your work I could check it but you didn't post your work.
See my response to your other post above. Note that I did NOT say the answer was 126 for #1 and 0.9 for #2. 126 or so means the answer is approximately that number. You are to do the work and calculate an exact answer for each and remember to report to the proper number of significant figures.