A compound of carbon, hydrogen, and oxygen was burned in oxygen, and 1 g of the compound produced 1.418 g #CO_2# and 0.871 g #H_2O#. (Question below?)
In another experiment, 0.1103 g of the compound was dissolved in 45 g of water. This solution had a freezing point of -0.0734 C. What is the molecular formula of this compound?
In another experiment, 0.1103 g of the compound was dissolved in 45 g of water. This solution had a freezing point of -0.0734 C. What is the molecular formula of this compound?
1 Answer
We gots....
Explanation:
We assess the molar quantities of carbon, and hydrogen, and oxygen.....
Now we check that we have accounted for all the mass....
Now the mass of carbon PLUS the mass of hydrogen is not equal to the starting mass of compound. The balance was due to oxygen.....because an analyst would never give you percentage oxygen....you would be expected to get this by difference....
And so ................
And thus with respect to oxygen there were...
And now (FINALLY!) we can address the empirical formula, by dividing thru by the lowest molar quantity...
And after all that arithmetic we gots to make another calculation to address the molecular mass....
...and so...
And so
And since the molecular formula is a muliple of the empirical formula, we gots