Bob Shell wrote: > On Feb 10, 2007, at 2:53 PM, David Weiss wrote: > >> The word "mole" refers to a number of particles, it is not a >> concentration unit. Molarity is a concentration unit, equal to >> moles of >> solute per liter of solution. If you have a solution of 0.100M NaOH, >> that is 0.100 moles of NaOH per liter of solution, that is 4.00 >> grams of >> NaOH in a liter of solution. Molality is used quite a bit too. > > > OK. How did you get from 0.100 moles per liter to 4.00 grams per > liter? That's the part I'm not getting. > > Bob > As has been stated, you need the molar mass, easy to calculate from the periodic table. I have a molar mass calculator (a program that calculates molar mass based on the chemical formula) - there must be such things on the net.
If I was to convert the above into mg NaOH/Liter solution: 0.100 moles NaOH 40.00 g NaOH 1000 mg NaOH ________________ x ______________ x _____________ = 1 liter NaOH (aq) mole NaOH 1 g NaOH 4,000 mg per liter of solution. If you start with nM I suppose is nanomoles/liter, so for instance 0.045 nmoles NaOH 1 mole NaOH 40.00 g 100 mg _________________ x _______________ x _______ x ________ 1 liter sol'n billion nmoles mole NaOH 1 g NaOH = 1.8 x 10 -6 mg/L If you want, I could send you a zipped file of my calculator (easy to use, small program, windows based, just type in the formula correctly, and it spits it out) Dave -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
