Maharashtra Board Class 8 Introduction to Acid and Base

Chemical Fertilizer Production: Acids, particularly sulfuric acid, are used in the production of chemical fertilizers.

Explosives Manufacturing: Acids play a role in the production of explosives.

Oil Purification: They are used in the purification of oils.

Medicines: Acids are used in the pharmaceutical industry for the synthesis of various medicines.

Dyes and Paints: Acids are involved in the production of dyes and paints.

Battery Manufacturing: Dilute sulfuric acid is used in the production of lead-acid batteries.

Water Sterilization: Dilute hydrochloric acid is used for the sterilization of water.

Paper Manufacturing: Acids are used in the production of white paper from wood pulp.

 

Select proper word given in bracket and fill in the blanks.

Main constituent of acid is………..[ hydrogen ions (H+)]

Main constituent of base is…….[ hydroxide ions (OH-).]

Tartaric acid is a …………. Acid.[ organic]

Match the pairs.

Group A      Group B

Tamarind         a. Acetic acid

Curd                b. Citric acid

Lemon             c. Tartaric acid

Vinegar           d. Lactic acid

Matched pairs:

Tamarind – c. Tartaric acid

Curd – d. Lactic acid

Lemon – b. Citric acid

Vinegar – a. Acetic acid

State true or false.

1. Oxides of metals are acidic in nature.
2. Table salt is acidic.
3. Metal corrodes due to salts
4. Salts are neutral.

Solution

1. False – Oxides of metals are generally basic in nature.
2. False – Table salt (sodium chloride, NaCl) is a neutral salt.
3. False – Metal corrosion is generally not caused by salts. It is often due to exposure to oxygen and moisture in the environment.
4. True – Salts are neutral compounds formed by the reaction between an acid and a base.

Classify following substances into acidic, basic and neutral group –

Hcl, Nacl, Mgo, Kcl, Cao, H2SO4,HNO3, H2O, Na2CO3

Acidic:

1. HCl (Hydrochloric acid)
2. H2SO4 (Sulfuric acid)
3. HNO3 (Nitric acid)

Basic:

1. MgO (Magnesium oxide)
2. CaO (Calcium oxide)

Neutral:

1. NaCl (Sodium chloride)
2. KCl (Potassium chloride)
3. H2O (Water)
4. Na2CO3 (Sodium carbonate)