Alkalis

Question 0

What can be inferred from the formulas of alkalis?

Answer 0

They are ionic compound that contain hydroxide ions in the compound.

Question 1

What information can be derived from the pH scale?

Answer 1

All alkalis have a pH higher than 7. Some alkalis are weaker than others hence they will show a lower pH than alkalis that are stronger.

Question 2

What is an alkali?

Answer 2

Substances that produces hydroxide ions in water.

Question 3

What condition is needed for alkalis to show their properties?

Answer 3

1. Alkalis must dissolves in water to separate the hydroxide ions from the metal ions in the ionic structure.
2. The hydroxide ions are responsible for the alkalinity of the solution.

Question 4

What are physical properties of alkalis?

Answer 4

They are colorless aqueous solutions that taste bitter and acts as electrolytes since they can conduct electricity.

Question 5

What are chemical properties of alkalis?

Answer 5

1. Cause indicators to change color, and they react with acids and ammonium compound.
2. Damp litmus paper from red to blue.
3. Methyl orange from orange to yellow.
4. Phenolphthalein from colorless to pink.

Question 6

How does an alkali react with an ammonium compound?

Answer 6

Reacts with ammonium compound to form salt, water and ammonia gas.

Question 7

What is a strong alkali?

Answer 7

It’s a soluble metal hydroxide that separate all the hydroxide ions from the metal ions in ionic structure when dissolved in water.
Eg. Sodium hydroxide, potassium hydroxide, calcium hydroxide.

Question 8

What is a weak alkali?

Answer 8

An alkali that ionizes partially in water to form hydroxide ions.

Question 9

Why is aqueous ammonia used in detergent?

Answer 9

It can remove grease by dissolving it.