Hydroxides

Definition

Hydroxides are chemical compounds containing the hydroxide ion, $OH^{-}$. They often form when metals react with water or oxygen.

5 Must Know Facts For Your Next Test

1. Hydroxides of alkali metals such as sodium hydroxide (NaOH) and potassium hydroxide (KOH) are highly soluble in water and are strong bases.
2. Transition metal hydroxides like iron(III) hydroxide (Fe(OH)_3) are generally less soluble and can form precipitates.
3. Aluminum hydroxide, Al(OH)_3, is amphoteric, meaning it can react with both acids and bases.
4. Calcium hydroxide, Ca(OH)_2, also known as slaked lime, is used in the preparation of mortar and plaster.
5. Hydroxides play a significant role in neutralization reactions where acids react with bases to form water and salts.

Review Questions

• What is the general solubility trend of alkali metal hydroxides compared to transition metal hydroxides?
• Explain why aluminum hydroxide is considered amphoteric.
• Describe a practical application of calcium hydroxide in construction.

Related terms

Oxidation:

The process by which an element loses electrons during a reaction, often involving oxygen.

Base: A substance that can accept hydrogen ions ($H^{+}$) or donate a pair of valence electrons to form a bond.

Amphoteric:

A term describing a substance that can react with both acids and bases.