Question

Iron(iii) oxide is formed when iron combines with oxygen in the air. How many moles of Fe2O3 are formed when 55.8 g or Fe reacts completely with oxygen?

4Fe(s)+3O 2(g) --> 2Fe2O3(s)

A. 0.25 mol
B. 0. 50 mol
C. O. 75 mol
D. 1.00 mol

Answer 1

Answer: The correct answer is Option B.

Step-by-step explanation:

To calculate the number of moles, we use the formula:

`Moles=\frac{\text{Given mass}}{\text{Molar mass}}`

• Moles of Iron

Molar mass of iron = 55.8 g/mol

Given mass of iron = 558.8

Putting values in above equation, we get:

`Moles=(55.8g)/(55.8g/mol)=1mole`

For the given chemical equation:

`4Fe(s)+3O_2(g)\rightarrow 2Fe_2O_3(s)`

By Stoichiometry,

4 moles of Iron produces 2 moles of Iron(III) oxide

So, 1 mole of Ion will produce =
`(2)/(4)* 1` = 0.5 mole of Iron (III) oxide.

Hence, the correct answer is Option B.