for each of the following explain how you would prepare 1.0L of a solution that is 0.10M in L+. repeat for concentrations of 1.0*100 ppm

to determine the concentration of ethanol in cognac a 5.00-mL sample of cognac is diluted 0.500L.Analysis of the diluted cognac gives an ethanol concentration of 0.0844M.what is the molar concentration of ethanol in the undiluted cognac?

Molar is molar the concentration of cognac in the diluted same is 0.084 mols/L as well as in the undiluted sample. You can prove this if you wish this way.

millimoles cognac in the 500 sample = mL x M = 500 x 0.084 = 42.2
millimoles cognac in the 5 mL sample is 42.2 x (5/500) = 0.422
Then M in the 5 mL sample is millimoles/mL = 0.422/5 = 0.0844 M :-)

Did you know?

Did you know that preparing a solution with a specific concentration involves careful measurements and calculations? To prepare a 1.0L solution that is 0.10M in L+, you would first need to determine the amount of L+ needed. This can be calculated by multiplying the molarity (0.10M) by the volume (1.0L), which gives you 0.10 moles of L+. To make the solution, you would weigh out a substance that contains L+ in the necessary amount. For example, if you have L+ ions in the form of a compound X, you would weigh out 0.10 moles of X. Then, dissolve this amount of X in a solvent such as water or another suitable solvent to make a final volume of 1.0L. Now, let's dive into preparing a solution with a concentration of 1.0 * 100 ppm. First, we need to convert ppm (parts per million) to molarity. Since 1 ppm is equivalent to 1 mg/L, and 1 mg is equal to 1/1000 of a gram, we can convert 1 ppm to 0.001 g/L. To prepare a 1.0L solution that is 1.0 * 100 ppm in L+, you would calculate the mass needed by multiplying the concentration (0.001 g/L) by the volume (1.0L). This gives you 0.001 grams of L+. To make the solution, weigh out 0.001 grams of a substance that contains L+, such as compound Y, and dissolve it in a suitable solvent to make a final volume of 1.0L. This will result in a solution that is 1.0 * 100 ppm in L+.