when a 424-g of iron powder is burned in an oxygen atmosphere, 0.606-g of a reddish brown oxide is obtained. Determine the empirical formula of the oxide.
Is 0.0606g
To determine the empirical formula of the oxide, we need to calculate the mole ratio of iron to oxygen.
First, let's calculate the number of moles of iron used in the reaction.
Molar mass of iron (Fe) = 55.845 g/mol
Number of moles of iron = mass of iron / molar mass of iron
Number of moles of iron = 424 g / 55.845 g/mol
Number of moles of iron = 7.59 mol
Next, let's calculate the number of moles of oxygen used in the reaction.
Molar mass of oxygen (O) = 16.00 g/mol
Number of moles of oxygen = mass of oxide - mass of iron
Number of moles of oxygen = 0.606 g / 16.00 g/mol
Number of moles of oxygen = 0.038 mol
Now, let's divide the number of moles of each element by the smallest number of moles to get the mole ratio.
Mole ratio of iron to oxygen = 7.59 mol / 0.038 mol
Mole ratio of iron to oxygen = 199.74
The empirical formula represents the simplest whole number ratio of atoms in a compound. Since it is not practical to have fractional atoms, we need to round the mole ratio to the nearest whole number.
Therefore, the empirical formula of the oxide is Fe₃O₈.
To determine the empirical formula of the oxide, we need to find the ratio of moles of iron to moles of oxygen in the compound.
First, let's calculate the moles of iron and oxygen in the reaction:
1. Convert the mass of iron powder (424 g) and the mass of the reddish brown oxide (0.606 g) to moles.
- Moles of iron = mass of iron / molar mass of iron
- Moles of oxygen = mass of oxide / molar mass of oxygen
The molar mass of iron (Fe) is 55.845 g/mol, and the molar mass of oxygen (O) is 15.999 g/mol.
Moles of iron = 424 g / 55.845 g/mol
Moles of oxygen = 0.606 g / 15.999 g/mol
Next, we need to determine the simplest whole number ratio between the moles of iron and oxygen. To find this ratio, we divide both the moles of iron and oxygen by the smaller of the two values.
Dividing both moles of iron and oxygen by the smaller value (moles of oxygen), we get:
Moles of iron = (moles of iron / moles of oxygen) * (moles of oxygen / moles of oxygen)
Moles of oxygen = (moles of oxygen / moles of oxygen) * (moles of oxygen / moles of oxygen)
Finally, we compare the ratio of moles of iron and oxygen to find the empirical formula.
From the calculation above, if we assume the moles of oxygen to be 1 (to simplify), the ratio of moles of iron to moles of oxygen is:
Moles of iron = (moles of iron / moles of oxygen)
Moles of oxygen = (moles of oxygen / moles of oxygen) = 1
Therefore, the empirical formula of the oxide is FeO.
424 g of Fe is 424/55.85 = 7.59 moles
Is that 0.606 g or 606 g of brown oxide?
Recheck your numbers. If it is 606 g, then 182 g or 11.38 moles are oxygen atoms. That is a 1.50:1 O/Fe ratio
The empirical formula is Fe2O3