Solid iron(iii) hydroxide decomposes to produce iron(iii) oxide and water vapor, according to the following reaction: 2fe(oh)3 → fe2o3 3h2o. if 0.75 l of water vapor is produced at stp,
a. how many grams of iron(iii) hydroxide were used?

The balanced chemical reaction is:

2Fe(OH)3 = Fe2O3 + 3H2O

We are given the amount of water vapor to be produced from the reaction. This will be the starting point of our calculations.

0.75 L H2O ( 1 mol / 22.4 L ) ( 2 mol Fe(OH)3 / 3 mol H2O ) ( 106.87 g / 1 mol ) = 2.39 g Fe(OH)3