What Is The PH Of A Solution Of Na2O In Water?
When sodium oxide (Na2O) is dissolved in water, it reacts with the water to form sodium hydroxide (NaOH). The reaction can be written as:
Na2O + H2O → 2 NaOH
Sodium hydroxide is a strong base and completely dissociates in water. Therefore, the pH of the solution will depend on the concentration of the sodium hydroxide that is formed.
Assuming that all of the sodium oxide dissolves in water, the concentration of sodium hydroxide can be calculated using the stoichiometry of the reaction. One mole of sodium oxide reacts with one mole of water to form two moles of sodium hydroxide. Therefore, the concentration of sodium hydroxide in the solution will be twice the concentration of sodium oxide.
If we assume that the solution is at standard conditions (25°C and 1 atm), then the solubility of sodium oxide in water is about 4 g/L. Therefore, the concentration of sodium hydroxide in the solution will be:
2 × (4 g/L) / 40.00 g/mol = 0.20 M
Since sodium hydroxide is a strong base, the pH of the solution can be calculated using the equation:
pH = 14 - log [OH-]
where [OH-] is the concentration of hydroxide ions. In this case, the concentration of hydroxide ions is equal to the concentration of sodium hydroxide, so:
pH = 14 - log 0.20
= 12.7
Therefore, the pH of a solution of Na2O in water is approximately 12.7.