Question

Is $\mathrm{NaOH}$ an acid or base?

Answer 1

Acid and base:

• According to the Arrhenius Theory of acid and bases, Arrhenius acid is defined as any substance that ionizes to give the${\mathrm{H}}^{+}$, or hydrogen, ion when it gets dissolved in water.
• Whereas an Arrhenius base is defined as any substance that gives ionizes to give the ${\mathrm{OH}}^{–}$, or hydroxide, ion when it gets dissolved in water.

$\mathrm{NaOH}$ is an acid or base:

• NaOH is represented as an Arrhenius base because it dissociates in water to Hydroxide $\left({\mathrm{OH}}^{–}\right)$and Sodium$\left({\mathrm{Na}}^{+}\right)$ ions, which can be shown as;

$\mathrm{NaOH}\left(\mathrm{s}\right)\to \mathrm{Na}\left(\mathrm{aq}\right)+{\mathrm{OH}}^{-}\left(\mathrm{aq}\right)$

• Also, Sodium Hydroxide $\left(\mathrm{NaOH}\right)$contains Sodium, which is an alkali metal that resides on the leftmost side of the periodic table.
• Hence it will form basic solutions as group 1 elements usually form the most basic solutions, which is one reason $\mathrm{Na}$ forms a strong base.

Hence, $\mathrm{NaOH}$ is a base.