Help determine its empirical and molecular formulas.?
2017-10-18 8:36 am
A compound containing only C, H, and O, was extracted from the bark of the sassafras tree. The combustion of 74.7 mg produced 203 mg of CO2 and 41.5 mg of H2O. The molar mass of the compound was 162 g/mol.
回答 (1)
2017-10-18 10:30 am
(0.203 g CO2) / (44.00964 g CO2/mol) × (1 mol C / 1 mol CO2) × (12.01078 g C/mol) = 0.055401 g C
(0.0415 g H2O) / (18.01532 g H2O/mol) × (2 mol H / 1 mol H2O) × (1.007947 g H/mol) = 0.0046438 g H
(0.0747 g total) - (0.055401 g C) - (0.0046438 g H) = 0.0146552 g O
(162 g/mol) x (0.055401 g C) / (0.0747 g total) / (12.01078 g C/mol) = 10.003
(162 g/mol) x (0.0046438 g H) / (0.0747 g total) / (1.007947 g H/mol) = 9.991
(162 g/mol) x (0.0146552 g O) / (0.0747 g total) / (15.99943 g O/mol) = 1.986
Round to the nearest whole numbers to find the molecular formula:
C10H10O2
The coefficients of the molecular formula have the common factor of 2, so divide by 2 to find the empirical formula:
C5H5O
(0.0415 g H2O) / (18.01532 g H2O/mol) × (2 mol H / 1 mol H2O) × (1.007947 g H/mol) = 0.0046438 g H
(0.0747 g total) - (0.055401 g C) - (0.0046438 g H) = 0.0146552 g O
(162 g/mol) x (0.055401 g C) / (0.0747 g total) / (12.01078 g C/mol) = 10.003
(162 g/mol) x (0.0046438 g H) / (0.0747 g total) / (1.007947 g H/mol) = 9.991
(162 g/mol) x (0.0146552 g O) / (0.0747 g total) / (15.99943 g O/mol) = 1.986
Round to the nearest whole numbers to find the molecular formula:
C10H10O2
The coefficients of the molecular formula have the common factor of 2, so divide by 2 to find the empirical formula:
C5H5O
收錄日期: 2021-04-18 18:01:32
原文連結 [永久失效]:
https://answers.yahoo.com/question/index?qid=20171018003640AAQrXLf