When steam (hot water) is passed over iron, hydrogen gas and iron (lll) oxide are formed. What mass of steam would be needed to react completely with 100.0 g of iron?

1 Answer
Mar 7, 2016

Answer:

The reaction requires 48.4 g of steam.

Explanation:

Step 1. Write the balanced equation.

#"2Fe" + "3H"_2"O" → "Fe"_2"O"_3 + "3H"_2#

Step 2. Calculate the moles of iron.

#100 cancel("g Fe") × "1 mol Fe"/(55.84 cancel("g Fe")) = "1.791 mol Fe"#

Step 3. Calculate the moles of #"H"_2"O"#.

#1.791 cancel("mol Fe") × ("3 mol H"_2"O")/(2 cancel("mol Fe")) = "2.686 mol H"_2"O"#

Step 4. Calculate the mass of #"H"_2"O"#.

#2.686 cancel("mol H"_2"O") × ("18.02 g H"_2"O")/(1 cancel("mol H_2"O"")) = "48.4 g H"_2"O"#