1. Iron reacts with oxygen according to the following equation:
Fe + O2→ Fe2O3
a. Balance the equation.
b. Assuming you start with 15.0 g of iron, how many dm3 of oxygen are required to react?
c. How many molecules of oxygen is this?
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a. To balance the equation, we need to ensure that the number of atoms of each element on the right side is the same as the left side. In this case, we have one iron atom on the left and two on the right, so we need to put a coefficient of 2 in front of Fe on the left side:
2 Fe + O2 → Fe2O3
Now, we have two iron atoms and two oxygen atoms on both sides, so the equation is balanced.
b. To determine the amount of oxygen required to react with 15.0 g of iron, we need to convert the mass of iron into moles using its molar mass. The molar mass of iron (Fe) is 55.85 g/mol.
Mass of iron = 15.0 g
Molar mass of iron = 55.85 g/mol
Number of moles of iron = Mass of iron / Molar mass of iron
= 15.0 g / 55.85 g/mol
Now, we can use the balanced equation to determine the mole ratio of oxygen to iron. From the balanced equation, we see that for every 2 moles of iron, 1 mole of oxygen is required.
Number of moles of oxygen = (Number of moles of iron) / 2
Finally, to convert the number of moles of oxygen into volume, we need to use the ideal gas law. At standard temperature and pressure (STP), 1 mole of any gas occupies 22.4 dm^3.
Volume of oxygen = (Number of moles of oxygen) * 22.4 dm^3/mol
Simply substitute the values into the respective formulas to calculate the answer.
c. To determine the number of molecules of oxygen, we need to convert the moles of oxygen into number of molecules.
Number of molecules = (Number of moles of oxygen) * (6.022 x 10^23 molecules/mol)
Substitute the calculated value of moles of oxygen into the formula to find the number of molecules.