Question

When iron reacts with oxygen in the air , it forms iron (III) oxide or rust .

How many grams of iron (III) Oxide would be formed if 2 moles of iron completely react with oxygen gas ?

A. 319.2 g

B. 159.6 g

C. 71.8 g

D. 143.6 g​

Answer 1

B. 159.6 g

Step-by-step explanation:

balanced reaction:

• 4Fe + 3O2 → 2Fe2O3

∴ moles taht react of Fe = 2 mol

∴ mm Fe = 55.845 g/mol

⇒ g Fe2O3 = ?

∴ moles Fe2O3 = ( 2 mol Fe )×( 2 mol Fe2O3/ 4 mol Fe ) = mol Fe2O3

∴ mm Fe2O3 = 159.6882 g/mol

⇒ g Fe2O3 = ( 1 mol Fe2O3 )×( 159.6882 g/mol) = 159.6882 g