Chapter 14 · Acids and Bases
14.3Bases: Properties and Examples
8 min · two checks
Predict
What do NaOH and NH₃ have in common as bases, and how do they differ?
The idea
- List properties of bases.
- Contrast hydroxide bases with ammonia.
Bases produce OH⁻ in water, feel slippery because they react with oils on skin (which is damage, not cleanliness), turn red litmus blue, and neutralize acids. Soluble metal hydroxides — NaOH, KOH, and to a useful extent Ca(OH)₂ — are the classic bases. Ammonia, NH₃, is a base even though its formula has no OH. It takes a proton from water and leaves OH⁻ behind.
Not every compound with oxygen and hydrogen is a base. Alcohols and water itself are not named as bases in this casual sense, though water will get a more careful role shortly. “Alkali” in ingredient lists usually means a base. Concentration still matters: 0.001 M NaOH is a base and will not behave like oven cleaner, which is concentrated sodium hydroxide.
Keep these
- Bases raise [OH⁻] and turn red litmus blue.
- NaOH and KOH are strong hydroxide bases.
- NH₃ is a base without an OH in the formula.