To determine the formula of the oxide formed when burning phosphorus, we need to analyze the ratio of the masses of phosphorus and the resulting phosphoric oxide.
The molar mass of phosphorus (P) is approximately 31 grams/mol, and the molar mass of oxygen (O) is about 16 grams/mol.
From the given information, we know that:
Mass of phosphorus burned = 6.19 grams Mass of phosphoric oxide produced = 14.19 grams
To calculate the number of moles of phosphorus and oxygen, we divide the given masses by their respective molar masses:
Moles of phosphorus = 6.19 grams / 31 grams/mol = 0.2 moles Moles of oxygen = (14.19 grams - 6.19 grams) / 16 grams/mol = 0.5 moles
Now, we need to determine the ratio of phosphorus to oxygen in the oxide. The simplest whole number ratio can be found by dividing the number of moles of each element by the smallest number of moles (in this case, 0.2):
Phosphorus: 0.2 moles / 0.2 moles = 1 Oxygen: 0.5 moles / 0.2 moles = 2.5
Since we want a whole number ratio, we multiply the ratio by 2 to get:
Phosphorus: 1 * 2 = 2 Oxygen: 2.5 * 2 = 5
The formula of the oxide can be determined by combining the symbols for phosphorus (P) and oxygen (O) in the ratio determined:
Phosphorus: P Oxygen: O
Therefore, the formula of the oxide formed when burning 6.19 grams of phosphorus and obtaining 14.19 grams of phosphoric oxide is P₂O₅.