Question

The number of moles of CaO formed when $3$ moles of $Ca$ reacts with $1$ mole of oxygen gas:

• A. $2$
• B. $1$
• C. $3$
• D. $\frac{3}{2}$

Answer 1

Answer: (A)

$2$

The following reaction takes place:

2Ca + O₂ → 2CaO

no. of moles of Ca = 3

no. of moles of O₂ = 1. Thus, O₂ is the limiting reagent. The stoichiometric coefficient ratio of O₂ and CaO is 1:2.

Hence, for 1 mole of O₂ , 2 moles of CaO will be formed. Option A is correct.