Question

Вторичный амин массой 7,2г сожгли, продукты горения пропустили через избыток раствора щелочи. Объем не прореагировавшего со щелочью газа составил 1,792дм2(н.у). Какое число атомов в составе одной молекулы амина?

Answer 1

6 хотя если посчитать может будет больше

Answer 2

Calculation of the Number of Atoms in a Molecule of Secondary Amine

To calculate the number of atoms in a molecule of secondary amine, we need to consider the given information about the mass of the amine, the volume of the unreacted gas, and the excess alkali solution.

Let's break down the problem step by step:

1. Determine the molar mass of the secondary amine: - The molar mass of the secondary amine is given as 7.2 g.

2. Calculate the number of moles of the secondary amine: - To calculate the number of moles, we divide the mass of the amine by its molar mass. - Number of moles = Mass / Molar mass - Number of moles = 7.2 g / Molar mass

3. Calculate the volume of the unreacted gas at standard temperature and pressure (STP): - The volume of the unreacted gas is given as 1.792 dm^3 (STP).

4. Apply the ideal gas law to find the number of moles of the unreacted gas: - The ideal gas law equation is PV = nRT, where P is pressure, V is volume, n is the number of moles, R is the ideal gas constant, and T is temperature. - At STP, the pressure is 1 atm and the temperature is 273 K. - Rearranging the equation, we get n = PV / RT. - Number of moles of unreacted gas = (1 atm * 1.792 dm^3) / (0.0821 atm·dm^3/mol·K * 273 K)

5. Determine the ratio of moles between the amine and the unreacted gas: - Since the amine is a secondary amine, it has one nitrogen atom per molecule. - The unreacted gas is likely to be nitrogen gas (N2), which has two nitrogen atoms per molecule. - Therefore, the ratio of moles between the amine and the unreacted gas is 1:2.

6. Calculate the number of moles of the unreacted gas: - Multiply the number of moles of the amine by the ratio of moles between the amine and the unreacted gas.

7. Calculate the Avogadro's number: - Avogadro's number is the number of atoms or molecules in one mole of a substance and is approximately 6.022 x 10^23.

8. Calculate the number of atoms in one molecule of the secondary amine: - Multiply the number of moles of the unreacted gas by Avogadro's number.

Now, let's perform the calculations using the given values:

1. Molar mass of the secondary amine: 7.2 g 2. Number of moles of the secondary amine: 7.2 g / Molar mass 3. Volume of the unreacted gas at STP: 1.792 dm^3 4. Number of moles of the unreacted gas: (1 atm * 1.792 dm^3) / (0.0821 atm·dm^3/mol·K * 273 K) 5. Ratio of moles between the amine and the unreacted gas: 1:2 6. Number of moles of the unreacted gas: Number of moles of the amine * Ratio of moles 7. Avogadro's number: 6.022 x 10^23 8. Number of atoms in one molecule of the secondary amine: Number of moles of the unreacted gas * Avogadro's number

Please note that we need the molar mass of the secondary amine to proceed with the calculations. If you have the molar mass, please provide it so that we can provide a more accurate answer.