Question

Phosphorus combines with oxygen to form two oxides. Find the empirical formula for each oxide of phosphorus if the percentage composition is 43.6% oxygen.

Answer 1

The empirical formulas for phosphorus(III) oxide and phosphorus(V) oxide can be determined from their stoichiometry, which are P4O6 and P4O10 respectively. These compounds feature a 2:3 and 2:5 ratio of phosphorus to oxygen by moles, and calculating empirical formulas from a percent composition involves converting percentages to moles and simplifying.

Step-by-step explanation:

The empirical formulas for the oxides of phosphorus with 43.6% oxygen can be determined by understanding their composition and stoichiometry. The two common oxides of phosphorus are phosphorus(III) oxide, P4O6, and phosphorus(V) oxide, P4O10. If we consider a 100 g sample for simplification, we would have 43.6 grams of oxygen in the mix. Using the atomic weights of phosphorus (approximately 30.97 g/mol) and oxygen (approximately 16.00 g/mol), we can calculate the mole ratio between phosphorus and oxygen in each oxide.

For phosphorus(III) oxide, the empirical formula is derived from the stoichiometry of P4O6, which inherently gives a ratio of 4:6 or 2:3 phosphorus to oxygen by moles. On the other hand, for phosphorus(V) oxide, the empirical formula comes from the stoichiometry of P4O10, which gives a ratio of 4:10 or 2:5 phosphorus to oxygen by moles. These are already empirical since they are the simplest whole number ratios.

Regarding the empirical formula from the percentage composition, you would convert the mass percentages to moles, then divide by the smallest number of moles to find the simplest whole number ratio. Since the problem states that the percentages are for oxygen, and these are two distinct compounds (one with a lower and one with a higher oxidation state of phosphorus), we would expect the mole ratio of phosphorus to oxygen to be different for each oxide. The actual calculation would require the percentage of phosphorus, which is missing from the question. Assuming the compound only contains phosphorus and oxygen, the rest of the sample (100% - 43.6%) would be phosphorus. This approach would then give us the respective mole ratios when divided by the atomic masses and simplified.

Answer 2

we are given with the percentage composition of oxygen in an oxide from phosphorus and oxygen equal to 43.6 percent. that is the phosphorus is equal to 56.4 percent. we divide each with the molar mass and divide each with the smaller quantity. P then is equal to 1 and O is equal to 1.5. In this case, the empirical formula is P2O3.