Question

214. В избытке воды растворили оксид фосфора(V) массой 6,30 г. Рассчитайте химическое количество фосфорной кислоты, содержащейся в полученном растворе.

Answer 1

Ответ: как-то так

Объяснение:

Answer 2

Calculation of the Chemical Amount of Phosphoric Acid

To calculate the chemical amount of phosphoric acid in the solution, we need to use the given information. It is stated that an excess of water was used to dissolve 6.30 grams of phosphorus pentoxide (P2O5), which is an oxide of phosphorus with a valence of +5 (V).

To calculate the chemical amount of phosphoric acid (H3PO4) in the solution, we can use the stoichiometry of the reaction between phosphorus pentoxide and water. The balanced equation for this reaction is:

P2O5 + 3H2O → 2H3PO4

From the balanced equation, we can see that 1 mole of phosphorus pentoxide reacts with 3 moles of water to produce 2 moles of phosphoric acid.

To calculate the chemical amount of phosphoric acid, we need to convert the mass of phosphorus pentoxide to moles using its molar mass. The molar mass of P2O5 is 141.94 g/mol.

Let's calculate the number of moles of phosphorus pentoxide:

Mass of P2O5 = 6.30 g Molar mass of P2O5 = 141.94 g/mol

Number of moles of P2O5 = Mass of P2O5 / Molar mass of P2O5

Now, we can calculate the number of moles of phosphoric acid using the stoichiometry of the reaction:

Number of moles of H3PO4 = (Number of moles of P2O5) x (2 moles of H3PO4 / 1 mole of P2O5)

Finally, we can calculate the mass of phosphoric acid using its molar mass:

Mass of H3PO4 = (Number of moles of H3PO4) x (Molar mass of H3PO4)

Please note that the molar mass of phosphoric acid (H3PO4) is 97.99 g/mol.

Let's perform the calculations:

Number of moles of P2O5 = 6.30 g / 141.94 g/mol Number of moles of H3PO4 = (Number of moles of P2O5) x (2 moles of H3PO4 / 1 mole of P2O5) Mass of H3PO4 = (Number of moles of H3PO4) x (Molar mass of H3PO4)

Now, let's calculate the values:

Number of moles of P2O5 = 6.30 g / 141.94 g/mol = 0.0443 mol Number of moles of H3PO4 = (0.0443 mol) x (2 mol H3PO4 / 1 mol P2O5) = 0.0886 mol Mass of H3PO4 = (0.0886 mol) x (97.99 g/mol) = 8.68 g

Therefore, the chemical amount of phosphoric acid (H3PO4) contained in the obtained solution is approximately 8.68 grams.

Please note that the calculations are based on the given information and the stoichiometry of the reaction between phosphorus pentoxide and water.