charge of elements increases by one as you move from left to right.
Answer: 19.8 l
Explanation:
1) Chemical equation:
2Ca + O₂ → 2CaO
2) Mole ratios: 2 mol Ca : 1 mol O₂ : 2 mol CaO
3) Convert 35.4 g of Ca to moles:
n = mass in grams / molar mass = 35.4 g / 40.1 g/mol = 0.883 mol
4) Volume proportion: 1 mol of gas at STP = 22.4 l
1 mol at STP 0.883 mol at STP
--------------------- = ------------------------------
22.4 l x
⇒ x = 0.883 mol × 22.4 l / 1 mol = 19.8 l ← answer
