Question

При сжигании органического вещества массой 40г образовалось 44,8л углекислого газа и 48г воды. Относительная плотность вещества по этану равна 2. Найдите молекулярную формулу органического вещества

Answer 1

Фото
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Answer 2

Calculation of the Molecular Formula of the Organic Substance

To find the molecular formula of the organic substance, we need to analyze the given information about the mass of carbon dioxide and water produced during the combustion.

Given: - Mass of organic substance = 40 g - Volume of carbon dioxide produced = 44.8 L - Mass of water produced = 48 g - Relative density of the substance with respect to ethane = 2

To calculate the molecular formula, we need to determine the number of moles of carbon dioxide and water produced.

1. Calculate the number of moles of carbon dioxide: - The molar volume of any gas at standard temperature and pressure (STP) is 22.4 L. - Using the volume of carbon dioxide produced (44.8 L), we can calculate the number of moles of carbon dioxide: ``` Moles of CO2 = Volume of CO2 / Molar volume at STP = 44.8 L / 22.4 L/mol = 2 mol ```

2. Calculate the number of moles of water: - The molar mass of water (H2O) is 18 g/mol. - Using the mass of water produced (48 g), we can calculate the number of moles of water: ``` Moles of H2O = Mass of H2O / Molar mass of H2O = 48 g / 18 g/mol = 2.67 mol (rounded to two decimal places) ```

3. Calculate the number of moles of carbon: - The molar mass of carbon (C) is 12 g/mol. - Using the mass of the organic substance (40 g), we can calculate the number of moles of carbon: ``` Moles of C = Mass of organic substance / Molar mass of C = 40 g / 12 g/mol = 3.33 mol (rounded to two decimal places) ```

4. Calculate the empirical formula: - The empirical formula represents the simplest whole-number ratio of atoms in a compound. - Divide the number of moles of each element by the smallest number of moles obtained in step 2 or 3 to get the empirical formula. - In this case, the smallest number of moles is 2 (from step 1). - The empirical formula is obtained by dividing the number of moles of each element by 2: - Moles of C = 3.33 mol / 2 = 1.67 mol (rounded to two decimal places) - Moles of H = 2.67 mol / 2 = 1.34 mol (rounded to two decimal places) - The empirical formula is therefore CH1.67O1.34.

5. Calculate the molecular formula: - The molecular formula represents the actual number of atoms of each element in a compound. - To find the molecular formula, we need to determine the ratio between the empirical formula and the molecular formula. - The relative density of the substance with respect to ethane is given as 2. - The molecular formula mass is twice the empirical formula mass. - The empirical formula mass can be calculated by adding the atomic masses of the elements in the empirical formula: - Empirical formula mass = (1.67 * atomic mass of C) + (1.34 * atomic mass of H) + (1 * atomic mass of O) - The atomic masses of C, H, and O are 12 g/mol, 1 g/mol, and 16 g/mol, respectively. - Calculate the empirical formula mass and multiply it by 2 to get the molecular formula mass. - Divide the molecular formula mass by the empirical formula mass to find the ratio between the two. - Multiply the subscripts in the empirical formula by this ratio to obtain the molecular formula.

Unfortunately, the search results provided do not contain the necessary information to calculate the molecular formula of the organic substance. The required atomic masses and additional information about the compound are not available in the snippets provided.

To accurately determine the molecular formula, we would need the complete molecular weight or additional information about the compound's structure or composition.