Answer to Question #236430 in Chemistry for Baaa

Question

calculate the mass of oxygen needed to react 10.0g of calcium to form calcium oxide

Answer 1

Solution:

Calculate the moles of calcium (Ca):

The molar mass of Ca is 40 g/mol

Hence,

(10.0 g Ca) × (1 mol Ca / 40 g Ca) = 0.25 mol Ca

Balanced chemical equation:

2Ca + O₂ → 2CaO

According to stoichiometry:

2 mol of Ca reacts with 1 mol of O₂

Thus, 0.25 mol of Ca reacts with:

(0.25 mol Ca) × (1 mol O₂ / 2 mol Ca) = 0.125 mol O₂

Calculate the mass of oxygen (O₂):

The molar mass of O₂ is 32 g/mol

Hence,

(0.125 mol O₂) × (32 g O₂ / 1 mol O₂) = 4 g O₂

Answer: 4 grams of oxygen (O₂).