I already worked these on my own, but would like a second opinion to make sure I

Question

I already worked these on my own, but would like a second opinion to make sure I didnt do it wrong.

For the answer to the first one I got 1.31 x 10^-9 mol/L and For the second one I got 8.32 x 10^-3 ( something doesnt seem to be adding up so its possible I did the math wrong) Help!

1) Estradiol has a molar mass of 272.4 g/mol. Determine the molarity of your unknown sample. (the concentration of our unknown sample was 357.246629 pg / mL)

2) Other molecules that are commonly measured in the blood are urea and glucose. Determine the molarity of a typical urea (60.1 g/mol) value of 50 mg/dL.

Explanation / Answer

Given:

Concentration of unknown sample:

357.246 pg/mL = 357.246 *10-12 g / 10-3 L = 3.57 * 10-7 g/L

1 pg = 10-12 g 1 mL = 10-3 L

Molar concentration = mass concentraion / Molar mass = 3.57 * 10-7 g/L / 272.4 g/mol = 1.31 * 10-9 mol/L

Molarity = 1.31 * 10-9 mol/L

Second case

Mass conc. = 50 mg/dL = 50 * 10-3 g / 10-1 L = 0.5 g/L

Molar mass = 60.1 g/mol

Molar concentration = 0.5 g/L / 60.1 g/mol = 8.319 * 10-3 mol/L

Molarity= 8.319 * 10-3 mol/L

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.