Lecture 3 – Bases & Alkalis

ACKNOWLEDGEMENT:

Figure	Source of Figure
Figure 2	lahuzulu.tumblr.com

Bases and Alkalis:

All metal oxides and hydroxides are bases and those that dissolve in water to form basic solutions are called Alkalis.

Properties of Alkalis:

1. Alkalis turn moist red litmus paper, blue.
2. Alkalis are soapy to touch: 
• Alkalis react with skin oils to form soap.
3. Alkalis react with acids to undergo neutralization reaction:

4. Alkalis react with ammonium salts in the presence of heat to form ammonia gas.

This gas can be detected by using moist red litmus paper. Ammonia being basic in nature, turns moist red litmus paper, blue.
Figure 2:

Using bases to maintain pH of soil:

Maintaining pH of soil is essential to ensure the growth and survival of healthy plants. Acidity of soil harms the plants by causing the plants to lose their water to the surrounding soil. This retards their growth. This condition can be treated by using calcium hydroxide pellets. Calcium hydroxide being basic in nature, neutralizes the acidity of the soil and ensures the proper growth of plants.