The mass of NaOH produced when 3.20 g of oxygen are formed from the reaction is 16 g
How to calculate the mass of NaOH produced?
First, we shall calculate the mass of sodium peroxide, Na₂O₂ needed to form 3.20 g of oxygen. Details below:

- Molar mass of Na₂O₂ = 78 g/mol
- Reacting mass of Na₂O₂ from equation = 2 × 78 = 156 g
- Molar mass of O₂ = 32 g/mol
- Mass of O₂ produced from the balanced equation = 1 × 32 = 32 g
- Mass of O₂ produced from reaction = 3.20 g
- Mass of Na₂O₂ needed =?
32 g of O₂ were produced from 156 g of Na₂O₂
Therefore,
3.20 g of O₂ will be produce from =
= 15.6 g of Na₂O₂
Now, we shall obtain the mass of NaOH produced from the reaction. Details below:

- Molar mass of Na₂O₂ = 78 g/mol
- Reacting mass of Na₂O₂ from equation = 2 × 78 = 156 g
- Molar mass of NaOH = 40 g/mol
- Mass of NaOH produced from the equation = 4 × 40 = 160 g
- Mass of Na₂O₂ that reacted = 15.6 g
- Mass of NaOH produced =?
From the balanced equation above,
156 g of Na₂O₂ reacted to produce 160 g of NaOH
Therefore,
15.6 g of Na₂O₂ will react to produce =
= 16 g of NaOH
Therefore, the mass of NaOH produced is 16 g
Complete question:
Oxygen is produced by the reaction of sodium peroxide and water.
2Na2O2(s) + 2H2O(l) ---> O2(g) + 4NaOH(aq)
How many grams of NaOH are produced when 3.20 g of O2 is formed?