TERM 3 – Chemistry

Hello faithful readers!

Due to my duty as a student is Mutiara Harapan High School, i must update my blog every term. So, in this term i would to discuss about acids, bases and alkali.

ACID 

definition : acid is a substance that produces hydrogen ions, H+, in aqueous solution.

properties of acids :

1. Acid have sour taste

2. Acids dissolve in water to form solutions which conduct electricity

3. Acid turns blue litmus paper into red\

4. Acids has pH scale < 7. I if is below 3 it is strong acid.

4. Acids react with reactive metals to form a salt and hydrogen gas

5. Acids react with carbonates and hydrogen carbonates to form a salt, water and carbon dioxide

6. Acids react with metal oxides and hydroxides to form a salt and water only

Uses of acids:

1. HCl (hydrocholric acids) : is used to clean impurities such as rust or scale from metals and aluminium alloys

2. CH3COOH (Ethanoic acids) : is used in vinegar to act as a food preservative and flavor enhancer

3. Phosphoric acids : is added to food and beverages to give them a sour taste

BASE

definition : is any metal oxide or hydroxide that reacts with an acid to produce a salt and water only

ALKALI

definition: an alkali is a substance that produces hydroxide ions, OH-, in aqueous solution.

properties:

1. Have bitter taste and feel soapy

2. Turns red litmus paper to blue

3. Alkalis react with acid to form a salt and water only

4. Alkalis, when heated with ammonium salts, give off ammonia gas

5. Alkalis react with a solution of one metal salt to give another metal salt and metal hydroxide

Uses of Bases and Alkalis

1. Magnesium Oxide : is used as antacid for relieving gastric pain and for making refractory bricks

2. Sodium hydroxide and potassium hydroxide: are used in the preparation of soap

3. Calcium hydroxide is used to reduce acidity in soil

 

 

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