Back to: Basic Science Primary 5
Welcome to Science class.
ACID AND BASES
INTRODUCTION
In this section, we shall be learning what Acids and Bases are.
At the end of the class pupils should be able to define an acid and a base. They would also be able to distinguish between the physical properties of acids and bases. They would be able to state the various uses acids and bases are put into in our daily lives.
WHAT IS AN ACID?
The word acid comes from the Latin word ‘acere’ which means ‘sour’. The sour taste found in the things that we drink are natural acids. These liquids taste sour because they contain acids. Some fruits taste sour because they have acids in them.
Examples of acidic fruits are:
- Vinegar
- Lime juice
- Orange
- Tomatoes
DEFINITION OF BASES
Bases are anything that has bitter tastes and have a soap-like texture. Bases, like baking soda or soap, are bitter. Examples of bases are:
- Soapy water
- Baking soda
- Black coffee
Note that some acids and bases are very strong and can be harmful.
THE pH SCALE
Whether a liquid is an acid or a base, it depends on the type of ions or charges in it. The liquids having a pH value between 0 to 7 are acid with 0 being the strongest acid while the liquids having pH values between 7 to 14 are bases with 14 being the strongest base.
PHYSICAL PROPERTIES OF ACIDS
When acid is placed in water, it can do the following:
- Conduct electricity
- Change blue litmus paper to red
- Acid have sour taste
- React with base and be neutralized.
PHYSICAL PROPERTIES OF BASE
Bases too can perform a number of tasks when placed in water such as:
- Conduct electricity
- Changes red litmus paper to blue
- Bases have bitter taste
- They are slippery like soaps.
USES OF ACIDS AND BASE
- Acids and bases are often used in science and technology.
- The batteries of cars and inverters contain a strong acid called sulphuric acid.
- Bases are used in manufacturing household cleaning products, baking soda, and as fertilizers for crops.
- To neutralize acidic wastes before discharging them into the environment.
EVALUATION
List 5 fruits that taste sour.
List 3 things that are basic in nature.
SUMMARY
An acid–base reaction is a chemical reaction that occurs between an acid and a base. It can be used to determine pH values of any substance or mixture. To identify acids from bases, and the strength of each, chemists use a pH scale. Seven is neutral. Anything with a pH below 7 is acidic. Anything with a pH above 7 is basic.
ASSIGNMENT
Define acid+base reaction
List two physical properties of an acid
List 2 physical properties of a base.
REFERENCE
https://www.sciencenewsforstudents.org/article/explainer-what-are-acids-and-bases
http://www.citycollegiate.com/acidbasesalt2.htm
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