The elemental analysis of an organic solid extracted from gumarabic ( a gummy su

Question

The elemental analysis of an organic solid extracted from gumarabic ( a gummy substance used in adhesive, ink, andpharmaceutical) showed that it contain 40.0 percent C, 6.7 percentH, and 53.3 percent O. a soultion of 0.551 g of the solid in 22.9 gof the solvent diphenyl gave a freezing point depression of 1.60degree C. Calculate the molar formula of the solid. (Kffor diphenyl is 8.00 degree C/m.) a) molar mass (g/mol)? b) molecular formula? The elemental analysis of an organic solid extracted from gumarabic ( a gummy substance used in adhesive, ink, andpharmaceutical) showed that it contain 40.0 percent C, 6.7 percentH, and 53.3 percent O. a soultion of 0.551 g of the solid in 22.9 gof the solvent diphenyl gave a freezing point depression of 1.60degree C. Calculate the molar formula of the solid. (Kffor diphenyl is 8.00 degree C/m.) a) molar mass (g/mol)? b) molecular formula?

Explanation / Answer

for the first part it wants us to find empircal formula so percent to mass mass to moles divide by smallest multiply tillwhole. 40g C 6.7 g H 53.3 g O 3.3 mol C 6.6molH 3.3 mol O so that will give us the empircal CH2O so lets find molal from given delta h = kf*molal 1.6=8*m m=.02 since we know that .02 is mols/kg solvent we multiply that by the kg of hte solvent which is .0229 to getmoles which is .00458 mols so now we have moles and grams was given as .551 we can get molarmass g/mol = 120.306 thats A now for b we know that the empircal is CH2O which has a mass of ofroughly 30 g/mol since the molar mass is 4 times 30 it means the formual needs to be quad so C4H8O4 is the molecular

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

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