Question

Sodium peroxide (Na2O2) is used to remove carbon dioxide from (and add oxygen to) the air supply in spacecrafts. It works by reacting with CO2 in the air to produce sodium carbonate (Na2CO3) and O2. 2 Na2O2(s) + 2 CO2(g) → 2 Na2CO3(s) + O2(g) What volume (in liters) of CO2 can be consumed at STP by 435 g Na2O2?

Answer 1

 The volume  (in liters)  of CO₂  that can  be consumed at STP by 435 g Na₂O₂  is  125 L of Co₂

calculation

2Na₂O₂(s)  +2 CO₂ (g)→  2 Na₂CO₃(s)  + O₂(g)

Step 1 : find the moles  of Na₂O₂

moles = mass÷  molar mass

from periodic table the  molar mass  of Na₂O₂ = (23 x2) +( 16 x2) = 78 g/mol

 moles= 435 g÷ 78 g/mol = 5.58 moles

Step 2: use the mole ratio to determine the moles of CO₂

from given equation  Na₂O₂ : CO₂ =2 :2 =1:1

Therefore the  moles of CO₂  is also = 5.58 moles

Step 3: find the volume  of CO₂  at STP

that is at STP      1  mole of a gas = 22.4 L

                          5.58 moles = ? l

by cross multiplication

= (5.58 moles x 22.4 L) / 1 mole = 125 L