Maharashtra Board Class 8 Science Solution Chapter 12 – Introduction to Acid & Base
Balbharati Maharashtra Board Class 8 Science Solution Chapter 12: Introduction to Acid & Base. Marathi or English Medium Students of Class 8 get here Introduction to Acid & Base full Exercise Solution.
Std | Maharashtra Class 8 |
Subject | General Science Solution |
Chapter | Introduction to Acid & Base |
(1) (i) Acid
(ii) Acid
(iii) Base
(2.) Write chemical names from given formulae.
H2SO4 – Sulphuric acid.
Ca(OH)2 – Calcium Hydrooxide.
HCl – Hydrochloric Acid.
NaOH – Sodium Hydroxide.
KOH – Potassium Hydroxide.
NH4OH – Ammonium Hydroxide.
(4) (a) Hydrogen acid is used for getting chloride salt.
(b) The rock must contain calcium carbonate.
(c) I can find the nature of that chemical by using Acid – Base indicates like litmus, of phenolphthalein, China rose extract etc.
(5) (a)
Acid |
Base |
(i) Acid release H+ ions in water. |
(i) Base release OH– ions in water. |
(ii) Acid has tendency to lose pair of electrons. |
(ii) Base has tendency to accept pair of electrons. |
(iii) Acids are sour in taste. |
(iii) Base are better in taste. |
(b) Indicators are substance which gives a prominent sign to identity the presence of acids & base in the solution. Salt is produced from the reaction of acids and base. So, salt are considered as natural. Due to this reason indicators are not effected in salt.
(c) When acid & bases react together, then it is known as neutralization process.
Ex: H+ + OH– -> H2O
(d) (i) Sulphuric acid is used to make other chemical in industry.
(ii) HCL is used in science lab.
(6.)
(a.) Main constituent of acid is ______
Ans. H+ ions.
(b.) Main constituent of base is ______
Ans. OH– ions.
(c.) Tartaric acid is a _______ acid.
Ans. Organic acid.
(7) (i) Tamarind – Tartaric acid.
(ii) Curd – Lactic acid.
(iii) Lemon – Citric Acid.
(iv) Vinegar – Acetic acid.
(8.) State true or false.
(a.) Oxides of metals are acidic in nature.
Ans. False.
(b.) Table salt is acidic.
Ans. True (Actually it is natural in nature)
(c.) Metal corrodes due to salts
Ans. Salts
(d.) Salts are neutral.
ans. True.
(9.) Classify following substances into acidic, basic and neutral group –
HCl – Acid.
NaCl – Acid.
MgO – Basic.
KCl – Acid.
CaO – Basic.
H2SO4 – Acid.
HNO3 – Acid.
H2O – Neutral.
Na2CO3 – Basic.