Question

What mass of iron will react with 50.0 L of steam at 250. °C and 1.00 atm of pressure?2Fe (s) + 3H2O (g) -> Fe2O3 (s) + 3H2 (g)

Answer 1

To solve this problem we need to know first how many mols of water we have. To do that we use the Ideal gas law with the that provided:

`\begin{gathered} PV=nRT \\ n=(PV)/(RT)=(1atm\cdot50L)/(0.082(amt\cdot L)/(K\cdot mol)\cdot523.15K)=1.166mol \end{gathered}`

according to the chemical equation we know that 3 mols of water react with 2 mols of iron, we can use this information as a conversion factor to know how many mols of iron react with 1.166 mols of water:

`1.166mols\text{ of water}\cdot\frac{2mols\text{ of Fe}}{3\text{ mols of water}}=0.777mols\text{ of Fe}`

and last we have to convert those mols into mass. To do that we use the molar mass of Iron 55.845g/mol:

`m_(Fe)=n_(Fe)\cdot Mm_(Fe)=0.777mols\cdot55.845g/mol=43.939\text{ g}`

the mas of Iron is 43.939g