How many grams of iron are in 21.6 g of iron(III) oxide?

2 Answers
Aug 19, 2016

Answer:

Approx. #15*g# of metal.

Explanation:

#"Moles of iron oxide, " Fe_2O_3# #=# #(21.6*g)/(159.69*g*mol)#

#=# #0.135*mol# with respect to the oxide.

But by the composition of the oxide, there are thus #2xx0.135*molxx55.8*g*mol^-1# #"iron metal"# #=# #??g#.

An extraordinary percentage of our budgets goes into rust prevention; #"iron(III) oxide"# is only part of the redox chemistry. Once you put up a bridge or a skyscraper, which is inevitably steel-based structure, it will begin to corrode.

Feb 7, 2017

Answer:

There are 15.1 g of iron in the sample.

Explanation:

Step 1. Calculate the molar mass of #"Fe"_2"O"_3#

#"molar mass" = "2 × 55.84 g Fe + 3 × 16.00 g O" = "111.68 g Fe + 48.00 g O" = "159.68 g Fe"_2"O"_3#

This tells us that there are 111.68 g #"Fe"# in 159.68 g #"Fe"_2"O"_3#.

Step 2. Calculate the mass of #"Fe"#

∴ In 21.6 g #"Fe"_2"O"_3#,

#"Mass of Fe" =21.6 color(red)(cancel(color(black)("g Fe"_2"O"_3))) × "111.68 g Fe"/(159.68 color(red)(cancel(color(black)("g Fe"_2"O"_3)))) = "15.1 g Fe"#