Question

W(C)= 81.8% W(H)= 18,2% p(н.у.)= 1,97 г/моль Найти: СxHy

Answer 1

Пусть вещества было 100г, тогда

m(C)=81.8 г

m(H)=18.2 г

Находим количество моль атомов каждого элемента:

n(C)=m/M=81.8г/(12г/моль)=6.817 моль

n(H)=m/M=18.2г/(1г/моль)=18.2 моль.

Вычисляем молярное соотношение, получаем эмпирическую формулу:

С:Н=6.817:18.2, делим все соотношение на меньшее число 6.817, получаем:

С:Н= 1:2.67 или, умножив на три

С:Н=3:8.

Итак, эмпирическая формула (С3Н8)n.

Если плотность при н.у. 1.97 г/л, то молярная масса равна: M((С3Н8)n)=p*Vm=1.97г/л*22.4л/моль=44 г/моль.

Затем, чтобы узнать молекулярную формулу, составляем уравнение:

12*3*n +8*1*n=44

44n=44

n=1

Таким образом, получаем C3H8.

Ответ:С3Н8 (пропан).

Удачи!

Answer 2

To find the empirical formula of the compound CxHy, we need to use the given weight percentages and molar mass of each element. The given weight percentages are:

W(C) = 81.8% W(H) = 18.2%

We also have the molar mass of hydrogen (H):

M(H) = 1.97 g/mol

Let's assume we have a 100g sample of the compound, which means:

1. The weight of carbon (C) = 81.8% of 100g = 81.8g
2. The weight of hydrogen (H) = 18.2% of 100g = 18.2g

Now, we need to find the moles of each element:

1. Moles of carbon (C) = weight of C / molar mass of C = 81.8g / (molar mass of C)
2. Moles of hydrogen (H) = weight of H / molar mass of H = 18.2g / 1.97 g/mol

To calculate the molar mass of carbon (M(C)), we need to know the exact value, as it was not provided in the question. Carbon can form various compounds with different molecular weights, so without that information, we can't determine the exact empirical formula.

Please provide the molar mass of carbon, and I'll be happy to help you find the empirical formula of the compound CxHy.