(a) Mass of C = molar mass of C/molar mass of CO2 x mass of CO2
= 12.01/44.01 x 16.43 = 4.484 mg
Mass of H = 2 x molar mass of H/molar mass of H2O x mass of H2O
= 2 x 1.008/18.02 x 6.74 = 0.754 mg
Mass of O = mass of sample - mass of C - mass of H
= 7.23 - 4.484 - 0.754 = 1.992 mg
Since moles = mass/molar mass
Moles of C : H : O = 4.484/12.01 : 0.754/1.008 : 1.992/16.00
= 0.3733 : 0.7480 : 0.1245
= 3 : 6 : 1
Empirical formula is C3H6O
(b) Mass of C = molar mass of C/molar mass of CO2 x mass of CO2
= 12.01/44.01 x 12.818 = 3.498 mg
Mass of H = 2 x molar mass of H/molar mass of H2O x mass of H2O
= 2 x 1.008/18.02 x 3.675 = 0.411 mg
Mass of N = mass of sample - mass of C - mass of H
= 4.725 - 3.498 - 0.411 = 0.816 mg
Since moles = mass/molar mass
Moles of C : H : N = 3.498/12.01 : 0.411/1.008 : 0.816/14.01
= 0.2913 : 0.4077 : 0.05824
= 5 : 7: 1
Empirical formula is C5H7N
Let the molecular formula be C5aH7aNa
Molecular mass = 12.01 x 5a + 1.008 x 7a + 14.01 x a = 160
81.116a = 160 => a = 2
Molecular formula is C10H14N2
If the substance has a molecular mass of 160 +/- 5 g/mol, what is its molecular formula?
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Suppose a substance has been prepared that is composed of carbon, hydrogen and nitrogen. When 0.1156 gram of this compound is reacted with oxygen, 0.1638 gram of carbon dioxide (CO2) and 0.1676 gram of water (H2O) are collected. If all the carbon in the compound is converted to CO2 Determine the mass of Carbon and Hydrogen in the sample. Calculate the percentage composition of Carbon, Nitrogen and Hydrogen in the substance. Calculate the mass of nitrogen in the substance. Calculate...
Suppose a substance has been prepared that is composed of carbon, hydrogen and nitrogen. When 0.1156 gram of this compound is reacted with oxygen, 0.1638 gram of carbon dioxide (CO2) and 0.1676 gram of water (H2O) are collected. If all the carbon in the compound is converted to CO2 Determine the mass of Carbon and Hydrogen in the sample. Calculate the percentage composition of Carbon, Nitrogen and Hydrogen in the substance. Calculate the mass of nitrogen in the substance. Calculate...
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a compound consisting of C, H, and O only has a molar mass of 262.3 g/mol. combustion of 0.1000 of this compound caused a 0.2014 increase in the mass of the CO2 absorber and a .07553 g increase in the mass of the H2O absorber. what is the empirical formula of the compound
Molecular Formula from Elemental Analysis and Molecular Mass Determination An unidentified covalent molecular compound contains only carbon, hydrogen, and oxygen. When 7.80 mg of this compound is burned, 18.12 mg of CO2 and 1.98 mg of H2O are produced. The freezing point of camphor is lowered by 26.4°C when 3.236 g of the compound is dissolved in 17.25 g of camphor (Kf = 40.0°C kg/mol). What is the molecular formula of the unidentified compound? Choose appropriate coefficients in the molecular...