So my chem experiment asks us: What is the molarity of a 6.0 ppm solution (it's a 6.0 ppm chlorophyll solution, hexane is the so
lvent) Now, I've found a few ways to solve for it but they both give me different values. If it's possible, could you just tell me which is right.
#1 Way: 6parts/1million --> 0.006g/L --> take 0.006g convert w/ molar mass chlorophyll (1 mole/ 893.49 g) --> 6.71524 *10^(-6) moles
put 6.71524 *10^(-6) over 1L --> 6.71524 *10^(-6) M
0R 6parts/1million --> 6g/1000,000g --> take 6g convert w/ molar mass chlorophyll (1 mole/ 893.49 g) --> 6.71524 *10^(-3) moles
use hexane's density to convert 1000,000g to (mL first then) L (density: 1mL/0.6548g) --> 1527.18388 L
put 6.71524 *10^(-3) moles over 1527.18388 L --> 4.397*10^(-6) M
OR 6parts/1million -->6g/1000,000g take 6g convert w/ molar mass chlorophyll (1 mole/ 893.49 g) --> 6.71524 *10^(-3) moles
put 6.71524 *10^(-3) moles over 1000,000 --> 6.71524 *10^(-9) M
I think the second one is the right one but I'm not sure. Could you please help me? Thanks!
The second approach is correct. The other two approaches are not correct because they are incomplete; first approach would have been right IF the 6.0 ppm was MEASURED in hexane. Third approach cannot be right since it calculates moles and grams but not L.