Understanding Base and Alkali – Key Differences
In chemistry, bases and alkalis are substances that neutralise acids. While they are often confused, they are not the same. Understanding the difference between base and alkali helps in chemistry, particularly in acid-base reactions.
What is a Base?
A base is a substance that reacts with acids to form salt and water. Bases can be soluble or insoluble in water.
Examples of Bases:
Copper(II) oxide (CuO)
Magnesium hydroxide (Mg(OH)₂)
Ammonia (NH₃)
What is an Alkali?
An alkali is a base that dissolves in water to produce OH⁻ (hydroxide) ions. All alkalis are bases, but not all bases are alkalis.
Examples of Alkalis:
Sodium hydroxide (NaOH)
Potassium hydroxide (KOH)
Calcium hydroxide (Ca(OH)₂)
Table of Differences – Base vs Alkali
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FAQs on Difference Between Base and Alkali | NEET
1. What is the difference between a base and an alkali with examples?
A base is any substance that can neutralise acids to form salt and water, while an alkali is a water-soluble base that produces hydroxide (OH⁻) ions in solution.
Examples:
Base (not alkali): Copper(II) oxide (CuO), Zinc hydroxide (Zn(OH)₂)
Alkali (soluble base): Sodium hydroxide (NaOH), Potassium hydroxide (KOH)
2. What is the difference between base and alkali in chemistry?
In chemistry, a base is any substance that can accept hydrogen ions (H⁺) or donate hydroxide ions (OH⁻). An alkali is a type of base that dissolves in water to produce hydroxide ions.
3. What is the difference between base and acid?
Base: A substance that neutralises acids and has a pH greater than 7. It accepts H⁺ ions or donates OH⁻ ions.
Acid: A substance that releases H⁺ ions in solution and has a pH less than 7.
4. What is the difference between alkali and base in simple words?
A base is a substance that reacts with acids to form salt and water, while an alkali is a water-soluble base that releases hydroxide ions (OH⁻) when dissolved in water.
5. Is alkali an acid or a base?
An alkali is a type of base. It is a water-soluble base that produces OH⁻ ions when dissolved in water. Example: Sodium hydroxide (NaOH).
6. What is the difference between alkali and alkaline?
Alkali: A specific type of base that dissolves in water (e.g., NaOH, KOH).
Alkaline: A term used to describe substances that have a pH greater than 7, meaning they have basic properties.
Example: Baking soda solution (NaHCO₃) is alkaline, but it is not a strong alkali.
7. Why are all alkalis bases but not all bases alkalis?
All alkalis are bases because they neutralise acids, but not all bases are alkalis because some bases do not dissolve in water.
Example:
Base (not alkali): Copper(II) oxide (CuO) (Insoluble)
Alkali: Sodium hydroxide (NaOH) (Soluble in water)
8. What are three examples of bases and alkalis?
Bases:
Copper(II) oxide (CuO)
Ammonia (NH₃)
Zinc hydroxide (Zn(OH)₂)
Alkalis:
Sodium hydroxide (NaOH)
Potassium hydroxide (KOH)
Calcium hydroxide (Ca(OH)₂)
9. How can you identify an alkali?
An alkali can be identified using litmus paper and pH indicators:
Turns red litmus paper blue
Has a pH greater than 7
Produces OH⁻ ions in water
Feels slippery to touch
Example: Sodium hydroxide (NaOH) is an alkali because it dissolves in water and turns red litmus paper blue.
