Iron (III) oxide is formed when Iron combines with oxygen in the air. How many grams of Fe₂O₃ are formed when 16.7 grams of reacts completely with oxygen? 4Fe + O₃ ---> 2Fe₂O₃

23.9g of Fe₂O₃ are produced

Explanation:

Are formed when 16.7g of Fe reacts completely...

Based on the reaction:

4Fe + O₃ → 2Fe₂O₃

4 moles of Iron react per 1 mole of O₃ producing 2 moles of Fe₂O₃.

To solve this question we need to convert the mass of iron to moles. The ratio of reaction is 2:1 -That is, 2 moles of Fe produce 1 mole of Fe₂O₃-. Thus, we can find the moles of Fe₂O₃ produced and its mass:

Moles Fe -Molar mass: 55.845g/mol-:

16.7g Fe * (1mol / 55.845g) = 0.299 moles of Fe

Moles Fe₂O₃:

0.299 moles Fe * (2 mol Fe₂O₃ / 4 mol Fe) = 0.150 moles Fe₂O₃

Mass Fe₂O₃ -Molar mass 159.69g/mol-:

0.150 moles Fe₂O₃ * (159.69g / mol) =

number of molecules / avogadro's number * molecule molecular = mass

explanation:

we define a gram-molecular weight as the mass of one mole of any element or compound. a mole contains avogadro's number of units (molecules) –  

6.022

x

10

23

. so, dividing the number of molecules by avogadro's number gives us the number of moles. multiplying that by the molecular weight gives us the mass. from the periodic table we find the gram-molecular weight of u to be238 and of f to be19. so,  

u

f

6

will have a gram-molecular weight of 352g.