Problem: Estrone, which contains only carbon, hydrogen, and oxygen, is a female sexual hormone that occurs in the urine of pregnant women. Combustion analysis of a 1.893-g sample of estrone produced 5.543 g of CO2 and 1.388 g H2 O. The molar mass of estrone is 270.36 g/mol .Find the molecular formula for estrone.

FREE Expert Solution

We’re being asked to determine the empirical formula for estrone composed of C, H, and O given the combustion analysis.


Recall that in combustion analysisa compound reacts with excess O2 to form products

For a compound composed of C, H, and O, the reaction looks like this:


CxHyOz + O2 (excess)  x CO2y H2O


This means we need to do the following steps:

Step 1: Calculate the mass of C and H in the compound.

Step 2: Calculate the mass of O in the compound.

Step 3:  Calculate the moles of C, H and O

Step 4: Determine the lowest whole number ratio of C, H, and O to get the empirical formula.

Step 5: Get the ratio of the molar mass and empirical mass to determine the molecular formula.


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Problem Details

Estrone, which contains only carbon, hydrogen, and oxygen, is a female sexual hormone that occurs in the urine of pregnant women. Combustion analysis of a 1.893-g sample of estrone produced 5.543 g of CO2 and 1.388 g H2 O. The molar mass of estrone is 270.36 g/mol .

Find the molecular formula for estrone.