Question

Напишите пжл решение:при сжигании 2,5 г вещества образуется 3,42 гводы и 5,57 г углекислого газа. В состав вещества входит и азот(23%).Какова молекулярная формула вещества

Answer 1

Решение в фотографии ............

Answer 2

Дано:
M(в-ва)=2,5г
М(воды)=3,42
М(CO2)=5,57
W(n2)=23%
Сначала находишь молярную массу
Потом массы элементов С и Н в веществе по пропорции
Вычисляешь массу третьего элемента( из массы всего вещества вычитаешь сумму масс С и Н)
Находишь отношение числа атомов
N(c):n(h):n( )
И потом по молярной массе смотришь какое это вещество.
Правильный ответ C3H9N

Answer 3

Problem Analysis

We are given the following information: - 2.5 grams of a substance is burned. - 3.42 grams of water and 5.57 grams of carbon dioxide are produced. - The substance also contains nitrogen, which makes up 23% of its composition.

We need to determine the molecular formula of the substance.

Solution

To find the molecular formula of the substance, we need to calculate the number of moles of each element present in the given quantities.

1. Calculate the number of moles of water (H₂O) produced: - The molar mass of water (H₂O) is 18 g/mol. - Number of moles of water = mass of water / molar mass of water - Number of moles of water = 3.42 g / 18 g/mol

2. Calculate the number of moles of carbon dioxide (CO₂) produced: - The molar mass of carbon dioxide (CO₂) is 44 g/mol. - Number of moles of carbon dioxide = mass of carbon dioxide / molar mass of carbon dioxide - Number of moles of carbon dioxide = 5.57 g / 44 g/mol

3. Calculate the number of moles of nitrogen (N₂) present in the substance: - Since nitrogen makes up 23% of the composition, we can assume that 23% of the substance's mass is due to nitrogen. - Mass of nitrogen = 23% of the mass of the substance - Mass of nitrogen = 23% of 2.5 g

4. Calculate the number of moles of nitrogen: - The molar mass of nitrogen (N₂) is 28 g/mol. - Number of moles of nitrogen = mass of nitrogen / molar mass of nitrogen

5. Determine the empirical formula of the substance: - The empirical formula represents the simplest whole number ratio of the elements present in the substance. - Divide the number of moles of each element by the smallest number of moles obtained. - Round the resulting ratios to the nearest whole number to obtain the empirical formula.

6. Determine the molecular formula of the substance: - The molecular formula represents the actual number of atoms of each element in a molecule. - The molecular formula is a multiple of the empirical formula. - To find the molecular formula, we need additional information, such as the molar mass of the substance or the molecular weight of the empirical formula.

Unfortunately, the given information does not provide enough details to determine the molecular formula of the substance. We would need additional information to proceed further.

Please provide any additional information you may have, such as the molar mass of the substance or the molecular weight of the empirical formula, so that we can assist you further.