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

Molecules of oxygen

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

Now 1 mole of iron will react with mole of oxygen

Thus 1.52 moles of iron will react with moles of oxygen

Number of atoms of oxygen in 1.14 moles

practical process described pest part of scientific investigation.

because practical knowledge is powerful then therotical knowledge.