Question

При сжигании 36 г органического соединения образовалось 52,8 г оксида углерода (4) и 21,6 г воды. Относительная молекулярная масса этого вещества равна 180. Выведите молекулярную формулу этого органического вещества

Answer 1

Дано:
m(CxHyOz)=36г
M(CxHyOz)=180г/моль
m(CO2)=52,8г
m(H2O)=21,6г
CxHyOz-?
Решение:
найдем массу C,H,O,входящих в состав органического соединения.Для этого составим пропорцию
(1 моль) 44г CO2 содержит 12г С
52,8г СО2 содержит хг С
х=52.8*12/44=14.4
18г H2O содержит 2г Н
21,6г Н2О содержит хг H
x=21.6*2/18=2.4
m(O)=36г-(2,4г+14,4г)=19,2г
находим мольные отношения:
n(C):n(H):n(O)=14.4г/(12г/моль):2.4г/1(г/моль):9,2г/(16г/моль)=1,2:2,4:1,2=1:2:1 (x:y:z)
составляем уравнение
12x+2x+16x=180
30x=180
x=6
C6H12O6

Answer 2

Calculation of the Molecular Formula of the Organic Compound

To determine the molecular formula of the organic compound, we need to analyze the given information about the mass of carbon dioxide (CO2) and water (H2O) produced during the combustion of the compound.

According to the information provided: - Mass of carbon dioxide (CO2) produced = 52.8 g - Mass of water (H2O) produced = 21.6 g - Relative molecular mass of the compound = 180 g/mol

To calculate the molecular formula, we need to find the number of moles of carbon dioxide and water produced. We can then use the molar ratios to determine the empirical formula of the compound.

1. Calculate the number of moles of carbon dioxide (CO2): - Molar mass of CO2 = 12.01 g/mol (carbon) + 2 * 16.00 g/mol (oxygen) = 44.01 g/mol - Number of moles of CO2 = Mass of CO2 / Molar mass of CO2 = 52.8 g / 44.01 g/mol = 1.2 mol

2. Calculate the number of moles of water (H2O): - Molar mass of H2O = 2 * 1.01 g/mol (hydrogen) + 16.00 g/mol (oxygen) = 18.02 g/mol - Number of moles of H2O = Mass of H2O / Molar mass of H2O = 21.6 g / 18.02 g/mol = 1.2 mol

3. Determine the empirical formula: - The empirical formula represents the simplest whole-number ratio of atoms in a compound. - Since the number of moles of carbon dioxide and water produced is the same (1.2 mol), the empirical formula will have the same number of carbon and oxygen atoms as well as the same number of hydrogen and oxygen atoms. - The empirical formula is therefore C1H1O1, which can be simplified to CHO.

4. Calculate the empirical formula mass: - The empirical formula mass is the sum of the atomic masses of the elements in the empirical formula. - Empirical formula mass = 12.01 g/mol (carbon) + 1.01 g/mol (hydrogen) + 16.00 g/mol (oxygen) = 29.02 g/mol

5. Determine the molecular formula: - The molecular formula represents the actual number of atoms of each element in a molecule. - To find the molecular formula, we need to divide the relative molecular mass of the compound (180 g/mol) by the empirical formula mass (29.02 g/mol). - Molecular formula = Relative molecular mass / Empirical formula mass = 180 g/mol / 29.02 g/mol ≈ 6.20 - Since the molecular formula should be a whole number multiple of the empirical formula, we can round 6.20 to the nearest whole number, which is 6. - The molecular formula is therefore C6H6O6.

Therefore, the molecular formula of the organic compound is C6H6O6.