Question

Дам 70 б. Помогите: определите число молекул, атомов и электронов в а)3,5 кг азота б) 5,2 г хрома.

Answer 1

А) число молекул-3500:14=250
число электронов-7
б) число молекул-5,2:52=0.1
число электронов-24

Answer 2

Calculating Number of Molecules, Atoms, and Electrons

To determine the number of molecules, atoms, and electrons in the given substances, we can use the following steps:

a) 3.5 kg of Nitrogen

Given: - Mass of nitrogen = 3.5 kg

Calculations: 1. Calculate the number of moles of nitrogen using the molar mass of nitrogen (N2). - Molar mass of nitrogen (N2) = 14.007 g/mol - Number of moles = (Given mass)/(Molar mass) - Number of moles of nitrogen = (3.5 kg) / (14.007 g/mol) = 250.035 moles

2. Calculate the number of molecules and atoms. - Number of molecules = (Number of moles) * Avogadro's number - Number of atoms = (Number of molecules) * 2 (since each molecule of nitrogen contains 2 nitrogen atoms)

3. Calculate the number of electrons. - Number of electrons = (Number of atoms) * 7 (since each nitrogen atom has 7 electrons)

b) 5.2 g of Chromium

Given: - Mass of chromium = 5.2 g

Calculations: 1. Calculate the number of moles of chromium using the molar mass of chromium (Cr). - Molar mass of chromium (Cr) = 51.996 g/mol - Number of moles = (Given mass)/(Molar mass) - Number of moles of chromium = (5.2 g) / (51.996 g/mol) = 0.1 moles

2. Calculate the number of molecules and atoms. - Number of molecules = (Number of moles) * Avogadro's number - Number of atoms = (Number of molecules)

3. Calculate the number of electrons. - Number of electrons = (Number of atoms) * 24 (since each chromium atom has 24 electrons)

Let's calculate the values using the given data and the above steps.