Question

Рассчитать относительную молекулярную массу веществ и массовые доли элементов в них: Na2O,SnO2,BaSO3

Answer 1

Молекулярная масса:Na2O= округленное число NA умножить на 2+16
и так все остальные

Answer 2

Calculating Relative Molecular Mass and Mass Percentages

To calculate the relative molecular mass and mass percentages of the elements in the given compounds, we can use the atomic masses of the elements from the periodic table. Then, we can apply the following formulas:

1. Relative Molecular Mass (Mr): - For a compound like Na2O, we calculate the relative molecular mass by adding the atomic masses of the elements present in the compound.

2. Mass Percentages: - To find the mass percentage of an element in a compound, we use the formula: \[ \text{Mass \% of element} = \frac{\text{Atomic mass of element} \times \text{Number of atoms of element}}{\text{Molecular mass of compound}} \times 100 \]

Let's calculate the relative molecular mass and mass percentages for the given compounds.

Sodium Oxide (Na2O)

The relative molecular mass of Na2O can be calculated as follows: - Atomic mass of Na = 22.99 g/mol - Atomic mass of O = 16.00 g/mol - Relative molecular mass (Na2O) = (2 * atomic mass of Na) + atomic mass of O

Relative Molecular Mass (Na2O): - \(2 \times 22.99 + 16.00 = 61.98 \, \text{g/mol}\) Now, let's calculate the mass percentages of sodium and oxygen in Na2O.

Mass Percentage of Sodium: - \(\frac{2 \times 22.99}{61.98} \times 100 \approx 74.17\%\) Mass Percentage of Oxygen: - \(\frac{16.00}{61.98} \times 100 \approx 25.83\%\)

Tin(IV) Oxide (SnO2)

The relative molecular mass of SnO2 can be calculated as follows: - Atomic mass of Sn = 118.71 g/mol - Atomic mass of O = 16.00 g/mol - Relative molecular mass (SnO2) = atomic mass of Sn + (2 * atomic mass of O)

Relative Molecular Mass (SnO2): - \(118.71 + (2 \times 16.00) = 150.71 \, \text{g/mol}\) Now, let's calculate the mass percentages of tin and oxygen in SnO2.

Mass Percentage of Tin: - \(\frac{118.71}{150.71} \times 100 \approx 78.80\%\) Mass Percentage of Oxygen: - \(\frac{2 \times 16.00}{150.71} \times 100 \approx 21.20\%\)

Barium Sulfite (BaSO3)

The relative molecular mass of BaSO3 can be calculated as follows: - Atomic mass of Ba = 137.33 g/mol - Atomic mass of S = 32.07 g/mol - Atomic mass of O = 16.00 g/mol - Relative molecular mass (BaSO3) = atomic mass of Ba + atomic mass of S + (3 * atomic mass of O)

Relative Molecular Mass (BaSO3): - \(137.33 + 32.07 + (3 \times 16.00) = 217.40 \, \text{g/mol}\) Now, let's calculate the mass percentages of barium, sulfur, and oxygen in BaSO3.

Mass Percentage of Barium: - \(\frac{137.33}{217.40} \times 100 \approx 63.17\%\) Mass Percentage of Sulfur: - \(\frac{32.07}{217.40} \times 100 \approx 14.74\%\) Mass Percentage of Oxygen: - \(\frac{3 \times 16.00}{217.40} \times 100 \approx 22.09\%\) These calculations provide the relative molecular masses and mass percentages of the elements in the given compounds.