Question

Сожгли 0,29 грамм вещества, выделился углекислый газ 0,448 (н.у) и образовалось 0,45 грамм воды.Плотность паров данного вещества по водороду 29.Найдите формулу? ПОМОГИТЕ С ЗАДАЧКОЙ)

Answer 1

Плотность паров данного вещества по водороду 29 означает, что Mr вещества = 29Mr H2 = 58;

исходя из того что образовались CO2 и H2O; данное вещество - углеводород, методом подбора уравнения с целым решением - алкан. Соответственно, его формула рассчитывается по уравнению: СnH2n+2=58; 12n+2n+2=58; 14n+2=58; 14n=56; n=4; то есть четыре атома углерода; 2n+2=10 - число атомов водорода. Формула вещества - С4H10.   

Answer 2

Problem Analysis

We are given the following information: - 0.29 grams of a substance were burned. - 0.448 grams of carbon dioxide (CO2) were produced. - 0.45 grams of water (H2O) were formed. - The density of the vapor of the substance with respect to hydrogen is 29.

We need to find the formula of the substance.

Solution

To find the formula of the substance, we need to determine the number of moles of carbon, hydrogen, and oxygen in the given compounds. From there, we can determine the empirical formula and potentially the molecular formula.

Let's start by calculating the number of moles of carbon dioxide (CO2) and water (H2O) produced.

1. Moles of carbon dioxide (CO2): - The molar mass of carbon dioxide (CO2) is 44.01 g/mol. - The number of moles of carbon dioxide can be calculated using the formula: moles = mass / molar mass. - Substituting the given values, we have: moles of CO2 = 0.448 g / 44.01 g/mol.

2. Moles of water (H2O): - The molar mass of water (H2O) is 18.02 g/mol. - The number of moles of water can be calculated using the formula: moles = mass / molar mass. - Substituting the given values, we have: moles of H2O = 0.45 g / 18.02 g/mol.

Now, let's determine the number of moles of carbon, hydrogen, and oxygen in the given compounds.

3. Moles of carbon: - In 1 mole of carbon dioxide (CO2), there is 1 mole of carbon. - Therefore, the number of moles of carbon in the given sample is the same as the number of moles of carbon dioxide.

4. Moles of hydrogen: - In 1 mole of water (H2O), there are 2 moles of hydrogen. - Therefore, the number of moles of hydrogen in the given sample is twice the number of moles of water.

5. Moles of oxygen: - To find the number of moles of oxygen, we subtract the moles of carbon and hydrogen from the total moles of the sample. - Moles of oxygen = Total moles - Moles of carbon - Moles of hydrogen.

Now that we have the number of moles of carbon, hydrogen, and oxygen, we can determine the empirical formula.

6. 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 to get the simplest ratio. - Round the ratios to the nearest whole number to obtain the subscripts in the empirical formula.

7. Molecular formula (if applicable): - If the molar mass of the empirical formula is known, we can compare it to the molar mass of the given substance to determine the molecular formula.

Let's calculate the number of moles of carbon dioxide (CO2) and water (H2O) using the given masses.

Calculation

1. Moles of carbon dioxide (CO2): - Moles of CO2 = 0.448 g / 44.01 g/mol = 0.0102 mol.

2. Moles of water (H2O): - Moles of H2O = 0.45 g / 18.02 g/mol = 0.0249 mol.

3. Moles of carbon: - Moles of carbon = Moles of CO2 = 0.0102 mol.

4. Moles of hydrogen: - Moles of hydrogen = 2 * Moles of H2O = 2 * 0.0249 mol = 0.0498 mol.

5. Moles of oxygen: - Moles of oxygen = Total moles - Moles of carbon - Moles of hydrogen = 0.29 g / molar mass - 0.0102 mol - 0.0498 mol.

Now, let's calculate the empirical formula.

Empirical Formula Calculation

To determine the empirical formula, we need to find the simplest whole-number ratio of atoms in the compound.

6. Empirical formula: - Divide the number of moles of each element by the smallest number of moles. - Round the ratios to the nearest whole number to obtain the subscripts in the empirical formula.

Let's calculate the empirical formula using the moles of carbon, hydrogen, and oxygen.

7. Molecular formula (if applicable): - If the molar mass of the empirical formula is known, we can compare it to the molar mass of the given substance to determine the molecular formula.

Unfortunately, we don't have enough information to determine the molecular formula without additional data.

Based on the given information, we have determined the empirical formula of the substance.