Question

Как вычислить молекулярную массу?

Answer 1

Если известны масса и количество вещества то по формуле масса в-ва делить на количество получим молекулярную массу

Answer 2

Calculating Molecular Mass

To calculate the molecular mass of a compound, you can use the formula:

Molecular Mass (M) = (number of atoms of element 1 * atomic mass of element 1) + (number of atoms of element 2 * atomic mass of element 2) + ...

For example, to calculate the molecular mass of Na2B4O7 * 10 H2O:

Molecular Mass (Na2B4O7 * 10 H2O) = 2 * atomic mass of Na + 4 * atomic mass of B + 7 * atomic mass of O + 10 * 2 * atomic mass of H + 10 * atomic mass of O

Using the given atomic masses: Molecular Mass (Na2B4O7 * 10 H2O) = 2 * 23 + 4 * 11 + 7 * 16 + 10 * 2 * 1 + 10 * 16

Molecular Mass (Na2B4O7 * 10 H2O) = 46 + 44 + 112 + 20 + 160

Molecular Mass (Na2B4O7 * 10 H2O) = 382 g/mol.

Additional Information

The molecular mass can also be calculated using the molar mass of each element and the number of atoms of each element in the compound. The molar mass of an element is the mass of one mole of atoms of that element and is expressed in grams per mole (g/mol).

The molar mass of a compound is the sum of the molar masses of the elements in the compound, taking into account the number of atoms of each element present.

Conclusion

Calculating the molecular mass of a compound involves summing the products of the number of atoms of each element and the atomic mass of that element. This provides a way to determine the mass of a molecule, which is essential for various chemical and scientific applications.