Question

Вивисти молекулярну формулу вуглеводню в якому масова частка Карбону -82.8% Гідрогену 17,2%. Густина речовин за нормальних умов 2,6 т/л.

Answer 1

1. Спочатку знайдемо масу 1 моль вуглеводню за густиною:

 1 л вуглеводню - це 2,6 г, а

 22,4 л______________х г, звідки х=22,4*2,6/1=58 г(приблизно)

 2.Ця маса необхідна для подальшого розрахування кількості атомів Гідрогену і Карбону у молекулі вуглеводню:

а) $n(C)=\frac{w(C)\cdot{Mr(CxHy)}}{Ar(C)\cdot100\%}=\frac{82,8\cdot58}{12\cdot100}=4$ 

б) $n(H)=\frac{w(H)\cdot{Mr(CxHy)}}{Ar(H)\cdot100\%}=\frac{17,2\cdot58}{1\cdot100}=10$

Значить формула вуглеводню:$C_4H_{10}$ - це бутан(насичений вуглеводень)

Answer 2

Molecular Formula of the Hydrocarbon

The molecular formula of a hydrocarbon with a mass fraction of carbon of 82.8% and hydrogen of 17.2% can be determined using the given information.

To calculate the molecular formula, we need to know the molar masses of carbon and hydrogen. The molar mass of carbon is approximately 12.01 g/mol, and the molar mass of hydrogen is approximately 1.008 g/mol.

Let's assume we have 100 grams of the hydrocarbon. From the given mass fractions, we can calculate the mass of carbon and hydrogen in the sample:

- Mass of carbon = 82.8% of 100 g = 82.8 g - Mass of hydrogen = 17.2% of 100 g = 17.2 g

Next, we need to convert the masses of carbon and hydrogen to moles by dividing them by their respective molar masses:

- Moles of carbon = 82.8 g / 12.01 g/mol ≈ 6.89 mol - Moles of hydrogen = 17.2 g / 1.008 g/mol ≈ 17.06 mol

Now, we need to find the simplest whole number ratio between the moles of carbon and hydrogen. To do this, we divide both values by the smaller value:

- Moles of carbon / Moles of hydrogen ≈ 6.89 mol / 6.89 mol ≈ 1 - Moles of hydrogen / Moles of hydrogen ≈ 17.06 mol / 6.89 mol ≈ 2.47

Since we want the simplest whole number ratio, we can round the ratio of hydrogen to the nearest whole number:

- Rounded ratio of hydrogen = 2

Therefore, the empirical formula of the hydrocarbon is CH2.

However, the given information also includes the density of the substance under normal conditions, which is 2.6 t/L. Unfortunately, the density alone is not sufficient to determine the molecular formula of the hydrocarbon. The density only provides information about the mass per unit volume and does not directly relate to the molecular formula.

To determine the molecular formula, additional information is needed, such as the molar mass of the compound or the molecular weight. Without this information, we cannot determine the specific molecular formula of the hydrocarbon.

Please let me know if there is anything else I can help you with!