When sodium reacts with water, the hydroxide formed is sodium hydroxide (NaOH). The reaction can be represented by the balanced chemical equation: 2Na+2H2O→2NaOH+H22\text{Na}+2\text{H}_2\text{O}\rightarrow 2\text{NaOH}+\text{H}_22Na+2H2O→2NaOH+H2 In this reaction, sodium displaces hydrogen from water, resulting in sodium hydroxide, a strong base, and the release of hydrogen gas. The reaction is exothermic and often vigorous, sometimes causing the hydrogen gas to ignite due to the heat produced. Sodium hydroxide formed in this way is dissolved in the water, making the solution alkaline.
Thus, the hydroxide formed when sodium reacts with water is sodium hydroxide (NaOH).
