1.2 moles of hydrogen 0.4 moles of phosphorus and 1.6 moles of Oxygen will be present
the atomic mass of one mole phosphoric acid is 98
and the atomic mass of 0.4 moles phosphoric acid is 39.2
98 gram phosphoric acid contents 3 moles hydrogen and 39.2 gram phosphoric acid contents 1.2 moles of hydrogen
calculate the mol number of phosphorus and oxygen in the unitary method

Introduction:
Phosphoric acid (H3PO4) is a chemical compound that consists of hydrogen (H), phosphorus (P), and oxygen (O). To determine the number of moles of hydrogen, phosphorus, and oxygen in 0.4 moles of phosphoric acid, we need to consider the stoichiometry of the compound.

Stoichiometry of Phosphoric Acid:
Phosphoric acid has a chemical formula of H3PO4, which means it contains 3 hydrogen atoms, 1 phosphorus atom, and 4 oxygen atoms.

Calculating the Moles of Hydrogen:
To calculate the moles of hydrogen in 0.4 moles of phosphoric acid, we need to consider the ratio of hydrogen atoms to phosphoric acid molecules. The ratio is 3:1, as there are 3 hydrogen atoms in each phosphoric acid molecule. Therefore, the number of moles of hydrogen can be calculated as follows:

Moles of Hydrogen = 3 * Moles of Phosphoric Acid
Moles of Hydrogen = 3 * 0.4
Moles of Hydrogen = 1.2 moles

Therefore, there are 1.2 moles of hydrogen in 0.4 moles of phosphoric acid.

Calculating the Moles of Phosphorus:
To calculate the moles of phosphorus in 0.4 moles of phosphoric acid, we again consider the ratio of phosphorus atoms to phosphoric acid molecules. The ratio is 1:1, as there is 1 phosphorus atom in each phosphoric acid molecule. Therefore, the number of moles of phosphorus is equal to the number of moles of phosphoric acid.

Moles of Phosphorus = Moles of Phosphoric Acid
Moles of Phosphorus = 0.4 moles

Therefore, there are 0.4 moles of phosphorus in 0.4 moles of phosphoric acid.

Calculating the Moles of Oxygen:
To calculate the moles of oxygen in 0.4 moles of phosphoric acid, we need to consider the ratio of oxygen atoms to phosphoric acid molecules. The ratio is 4:1, as there are 4 oxygen atoms in each phosphoric acid molecule. Therefore, the number of moles of oxygen can be calculated as follows:

Moles of Oxygen = 4 * Moles of Phosphoric Acid
Moles of Oxygen = 4 * 0.4
Moles of Oxygen = 1.6 moles

Therefore, there are 1.6 moles of oxygen in 0.4 moles of phosphoric acid.

Summary:
In summary, 0.4 moles of phosphoric acid (H3PO4) contain 1.2 moles of hydrogen, 0.4 moles of phosphorus, and 1.6 moles of oxygen. The stoichiometry of the compound allows us to determine the number of moles of each element present based on the given amount of phosphoric acid.