Question

If 84.9 grams of solid iron reacts with oxygen gas, how many molecules of oxygen will react

Answer 1

Molecules of oxygen
`= 6.86 * 10^(23)`

Step-by-step explanation:

The balanced equation of reaction between iron and oxygen is

4 Fe + 3 O2 → 2 Fe2O3

4 moles of iron react with 3 moles of oxygen.

Mass of one mole of iron is 55.845

number of iron moles in 84.9 grams of solid iron is equal to

`(84.9)/(55.845) \\= 1.52`

Now 1 mole of iron will react with
`(3)/(4) = 0.75` mole of oxygen

Thus 1.52 moles of iron will react with
`0.75 * 1.52 = 1.14` moles of oxygen

Number of atoms of oxygen in 1.14 moles

`1.14* 6.02 * 10^(23)\\`

`= 6.86 * 10^(23)`