Acids ~ The word ‘Acid’ came from Latin word ‘Acidus or Acere’ which means sour.
~Sour taste is the most common characteristic of acid. ~ Acid turns blue litmus paper red. There are many substances which contain acid and hence taste sour, such as curd, tamarind, lemon, etc.
Types of Acid
~ Acids which are obtained from natural sources are called natural acid or organic acid.
Name of Acid Source Acetic acid Vinegar Ascorbic acid Amla Guava Citric acid Lemon Lactic acid Sour milk Methanoic acid Ant sting
Mineral Acids ~ Acids that prepare from mineral are known as mineral acids, inorganic acids, man-made acids or synthetic acid, such as hydrochloric acid, sulphuric acid, nitric acid, etc.
Reaction of acids with metal:
Acids give hydrogen gas along with respective salt when they react with a metal.
METAL + ACID ------> SALT + HYDROGEN GAS
~Hydrogen gas and zinc chloride are formed when hydrochloric acid reacts with zinc metal.
Zn + 2HCl -------> ZnCl2 + H2
Which of the following gives the correct increasing order of acidic strength?
(a) Water < Acetic acid < Hydrochloric acid
(b) Water < Hydrochloric acid < Acetic acid
(c) Acetic acid < Water < Hydrochloric acid
(d) Hydrochloric acid < Water < Acetic acid