if 11.80 g of iron reacts with 5.06 g of oxygen, determine the empirical formula of the oxide?
moles = grams/atomic mass
mols Fe atoms = 11.8/55.85 = 0.211
mols O atoms = 5.06/16 = 0.316
Now want to find the ratio of these two to each other with the smallest number being no less than 1.00. The easy way to do that is to divide both numbers of the smallest; i.e.,
Fe = 0.211/0.211 = 1.00
O = 0.316/0.211 = 1.498 which rounds to 1.5
We know that compounds exist with atoms in the ratio of small whole numbers so we can see that a ratio of 1.00 to 1.5 is 2 to 3 or if we multiply both numbers by 2 to get whole numbers it will be Fe of 2 and O of 3 so the simplest empirical formula is Fe2O3.
thank you sir for your help
To determine the empirical formula of the oxide, follow these steps:
Step 1: Convert the masses of iron and oxygen to moles.
Molar mass of iron (Fe) = 55.85 g/mol
Molar mass of oxygen (O) = 16.00 g/mol
Moles of iron: 11.80 g / 55.85 g/mol = 0.211 mol
Moles of oxygen: 5.06 g / 16.00 g/mol = 0.316 mol
Step 2: Find the mole ratio between iron and oxygen.
Divide the moles of each element by the smallest number of moles.
Moles of iron = 0.211 mol / 0.211 mol = 1 (rounded to the nearest whole number)
Moles of oxygen = 0.316 mol / 0.211 mol = 1.5 (rounded to the nearest whole number)
Step 3: Multiply each mole ratio by a whole number to obtain whole numbers for the empirical formula.
Empirical formula: FeOₓ (where "x" represents the number of oxygen atoms)
Since the mole ratio for oxygen is 1.5, we need to multiply both the number of iron and oxygen atoms by 2 to get a whole number ratio.
Empirical formula: Fe₂O₃
Therefore, the empirical formula of the oxide is Fe₂O₃.
To determine the empirical formula of the oxide formed when iron reacts with oxygen, you need to find the ratio of the elements in the compound.
1. Start by converting the given mass of each element into moles using their molar masses:
- Iron (Fe): 11.80 g ÷ molar mass of Fe (55.85 g/mol) = 0.211 mol
- Oxygen (O): 5.06 g ÷ molar mass of O (16.00 g/mol) = 0.316 mol
2. Next, find the simplest whole-number ratio by dividing each element's mole value by the smallest value obtained. In this case, iron has the smaller mole value, so divide both values by 0.211 (Fe's mole value):
- Iron: 0.211 mol ÷ 0.211 mol = 1
- Oxygen: 0.316 mol ÷ 0.211 mol = 1.498
3. Round the resulting values to their nearest whole numbers while maintaining a whole-number ratio:
- Iron: 1
- Oxygen: 1.5
4. Finally, multiply each value by 2 to obtain the simplest whole-number ratio:
- Iron: 1 × 2 = 2
- Oxygen: 1.5 × 2 = 3
Therefore, the empirical formula of the oxide formed is Fe₂O₃.