posted by mj on .
Convert .25 L of a .025 M solution of NaCL starting with solid NaCI and water
Convert to what?
the question actually reads "how would you MAKE .25L of a 0025M solution of NaCL starting with solid NaCL and water? 2nd Q: ends with starting with 2.0M NaCL?
Based on a lab that we haven't even had yet.....lost.
How many moles NaCl do you want? That is M x L = 0.25L x 0.0025M = 0.000625 mol.
Then mol NaCl = grams NaCl/molar mass NaCl
g = mol x molar mass = about 0.0006 x 58 or so = about 0.036g NaCl.
For the second one.
mL1 x M 1 = mL2 x M2
which is the dilution formula. You may have seen it as c1v1 = c2v2.
Luckily I can ask for more help tomorrow...lol
Is the formula different for "how would you make 40mL of 30%ETOH starting with 75% ETOH and water" different (because it's all liquid vs. solid and liquid?) txs
How many grams each of cacodylic acid and sodium cacodylate trihydrate, do you need to add to 2.00 L of water to prepare a pH 5.60 buffer solution with a total buffer
concentration ([(CH3)2AsO2H] + [(CH3)2AsO2
-]) equal to 0.0100 M?
Sometimes we can make sense of questions when they lack completeness because we know the background but ONLY when screen names don't change. I don't understand the last two and I don't know if I am dealing with the same poster or not. Please repost as a new question at the top of the page; also, it helps if you don't change screen names.