Question

Помогите, пожалуйста!При горении углеводорода массой 3,36г получили 10,56г углекислого газа и 4,32г воды. Относительная плотность вещества по метану равна 3,5. Установите молекулярную формулу углеводорода.Заранее спасибо!!!

Answer 1

С4H8

Либо С=С-С-С

С-С

|     |

C-C

 

Answer 2

Calculation of Moles and Molar Mass

To determine the molecular formula of the hydrocarbon, we need to calculate the number of moles of carbon and hydrogen in the given mass of the hydrocarbon.

Let's assume the molecular formula of the hydrocarbon is CxHy, where x represents the number of carbon atoms and y represents the number of hydrogen atoms.

Given: - Mass of hydrocarbon = 3.36 g - Mass of carbon dioxide (CO2) produced = 10.56 g - Mass of water (H2O) produced = 4.32 g - Relative density of the substance with respect to methane (CH4) = 3.5

To calculate the number of moles, we need to use the molar mass of each compound involved.

The molar mass of carbon dioxide (CO2) is calculated as follows: - The molar mass of carbon (C) = 12.01 g/mol - The molar mass of oxygen (O) = 16.00 g/mol - The molar mass of carbon dioxide (CO2) = (12.01 g/mol) + 2*(16.00 g/mol) = 44.01 g/mol

The molar mass of water (H2O) is calculated as follows: - The molar mass of hydrogen (H) = 1.01 g/mol - The molar mass of water (H2O) = 2*(1.01 g/mol) + 16.00 g/mol = 18.02 g/mol

Calculation of Moles of Carbon and Hydrogen

Let's calculate the number of moles of carbon and hydrogen in the given mass of the hydrocarbon.

The number of moles of carbon dioxide (CO2) produced can be calculated using its molar mass: - Moles of CO2 = Mass of CO2 / Molar mass of CO2 = 10.56 g / 44.01 g/mol

The number of moles of water (H2O) produced can be calculated using its molar mass: - Moles of H2O = Mass of H2O / Molar mass of H2O = 4.32 g / 18.02 g/mol

Since the hydrocarbon contains carbon and hydrogen, we can write the following equations based on the number of moles:

Equation 1: Moles of carbon = x Equation 2: Moles of hydrogen = y

From the balanced chemical equation of the combustion reaction, we know that: 1 mole of carbon dioxide (CO2) is produced from 1 mole of carbon (C). 1 mole of water (H2O) is produced from 2 moles of hydrogen (H).

Using these relationships, we can write the following equations:

Equation 3: Moles of CO2 = Moles of carbon Equation 4: Moles of H2O = 2 * Moles of hydrogen

Substituting the calculated values into the equations, we have:

Equation 3: Moles of CO2 = x Equation 4: Moles of H2O = 2y

Calculation of the Molecular Formula

To find the molecular formula of the hydrocarbon, we need to determine the values of x and y.

From Equation 3, we know that Moles of CO2 = x. Substituting the calculated value of Moles of CO2, we have:

x = Moles of CO2 = 10.56 g / 44.01 g/mol

From Equation 4, we know that Moles of H2O = 2y. Substituting the calculated value of Moles of H2O, we have:

2y = Moles of H2O = 4.32 g / 18.02 g/mol

Simplifying the equations, we get:

x = 0.2397 mol y = 0.2397 mol / 2 = 0.1199 mol

Now, we can calculate the molar mass of the hydrocarbon using the given relative density.

The relative density of the substance with respect to methane (CH4) is given as 3.5. The molar mass of methane (CH4) is 16.04 g/mol.

The molar mass of the hydrocarbon can be calculated using the following equation:

Molar mass of hydrocarbon = (Relative density) * (Molar mass of methane)

Molar mass of hydrocarbon = 3.5 * 16.04 g/mol

Determining the Molecular Formula

To determine the molecular formula of the hydrocarbon, we need to find the empirical formula first.

The empirical formula represents the simplest whole-number ratio of atoms in a compound.

To find the empirical formula, we divide the number of moles of each element by the smallest number of moles obtained.

In this case, the smallest number of moles obtained is 0.1199 mol.

Dividing the number of moles of carbon and hydrogen by 0.1199 mol, we get:

Empirical formula: C1H1

Now, to find the molecular formula, we need to determine the ratio between the empirical formula and 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 know the molar mass of the empirical formula.

The molar mass of the empirical formula (C1H1) can be calculated as follows: - The molar mass of carbon (C) = 12.01 g/mol - The molar mass of hydrogen (H) = 1.01 g/mol - The molar mass of the empirical formula (C1H1) = (12.01 g/mol) + (1.01 g/mol) = 13.02 g/mol

Now, we can calculate the ratio between the molar mass of the hydrocarbon and the molar mass of the empirical formula:

Ratio = Molar mass of hydrocarbon / Molar mass of empirical formula

Ratio = (3.5 * 16.04 g/mol) / 13.02 g/mol

Simplifying the equation, we get:

Ratio = 4.294

Since the ratio is approximately 4, we can multiply the empirical formula (C1H1) by 4 to obtain the molecular formula:

Molecular formula = C4H4

Therefore, the molecular formula of the hydrocarbon is C4H4.

Note: The given search results did not provide specific information related to this question. The calculation and explanation provided above are based on the principles of stoichiometry and molar mass calculations.