Class 10 Science

Chemical Properties of Acid

These notes are based on the chapter Acids Bases and Salts from NCERT book based on CBSE syllabus.

  • Types of acid
  • Reaction of acid with metal

What is acid?

Acid is a substance which has sour taste and which turns blue litmus paper to red. If a substance tastes sour then it must contain acid. Curd, tamarind, lemon, etc. tase sour because they contain acid. If a substance does not contain acid, it does not taste sour.

Types of Acids

What are different types of acid?

Acids are divided into two types on the basis of their occurrence, viz. Natural acids and Mineral acids.

  1. Natural Acid: Acids which are obtained from natural sources are called natural acid. These acids are also called organic acid because they comes from living beings. Examples: vinegar, citric acid, tartaric acid, etc.
  2. Mineral Acids: Acids which are prepared from mineral are known as mineral acids. They are also called inorganic acids, man-made acids or synthetic acid. Examples: hydrochloric acid, sulphuric acid, nitric acid, etc.

Organic acids and their sources

  • Acetic acid: Vinegar
  • Ascorbic acid: Guava, amla
  • Citric acid: Lemon, orange and other citrus fruits
  • Lactic acid: Sour milk, curd
  • Methanoic acid: Ant sting, nettle sting
  • Oxalic acid: Tomato
  • Tartaric acid: Tamarind

Reaction of acids with metal

What happens when an acid reacts with metals? Acids give hydrogen gas along with respective salt when they react with a metal.

Metal + Acid ⇨ Salt + Hydrogen

Example 1

Hydrogen gas and zinc chloride are formed when hydrochloric acid reacts with zinc metal.

Zn + 2HCl ⇨ ZnCl2 + H2

Example 2

Hydrogen gas and sodium chloride are formed when hydrochloric acid reacts with sodium metal.

2Na + 2HCl ⇨ 2NaCl + H2

Example 3

Hydrogen gas and iron chloride are formed when hydrochloric acid reacts with iron.

Fe + 2HCl ⇨ FeCl2 + H2

Example 4

Hydrogen gas and zinc sulphate are formed when zinc metal reacts with sulphuric acid

Zn + H2SO4 ⇨ ZnSO4 + H2

Test for hydrogen gas: The gas evolved after reaction of acid with metal can be tested by bringing a burning candle near it. If the candle burns with pop sound, then it confirms the evolution of hydrogen gas. This is the characteristic test for hydrogen gas.

Reaction of Metal with Nitric Acid

What happens when a metal reacts with nitric acid? When a metal reacts with nitric acid then hydrogen gas is not formed. It happens because of following reason.

Nitric acid is a strong oxidising agent. Nitric acid oxidises H2 to make water. In the reaction with metal, nitric acid itself gets reduced to oxides of nitrogen such as NO2 or NO or N2O

Reaction between nitric acid and copper

In this reaction of nitric acid with copper, nitrogen oxide, water and copper nitrate are formed. Hydrogen gas is not formed in this reaction.

3Cu + 8HNO3 → 3Cu(NO3)3 + 2NO + 4H2O

But magnesium and manganese react with very dilute nitric acid (HNO3 to produce H2 gas.

Reaction between nitric acid and magnesium

In this reaction of nitric acid with magnesium, hydrogen gas and magnesium nitrate are formed.

Mg + 2HNO3 → Mg(NO3)2 + H2

Reaction between nitric acid and manganese

In this reaction of nitric acid with manganese, hydrogen gas and manganee nitrate are formed.

Mn + 2HNO3 → Mn(NO3)2 + H2

Reaction between nitric acid and zinc

In this reaction of nitric acid with zinc, hydrogen gas and zinc nitrate are formed.

Zn + 2HNO3 → Zn(NO3)2 + H2


More from this Lesson

Chemical Reaction

Chemical change is called chemical reaction. A new substance is formed after chemical reaction.

Acid Base Salt

Acids and bases dissociate into ions in aqueous solution. Salt is formed on reaction between acid and base.

Metals Non-metals

Elements are of two types: metals and non-metals which have different chemical and physical properties.

Carbon Compounds

Compounds of carbon are called organic compounds and are millions in number.

Periodic Classification

As per modern periodic classification, properties of elements are periodic function of their atomic number.

Life Processes

Biological processes essential to continue life are called life processes.

Control Coordination

In complex animals, control and coordination of various functions are achieved by nervous system and hormones.

Reproduction

The process by which a living being produces its offspring is called reproduction.

Heredity Evolution

Inheritance of traits from one generation to next is called heredity. All living beings have evolved from a common ancestor.

Light Reflection

Bouncing back of light from a shiny surface is called reflection of light.

Light Refraction

Deviation in path of light when light travels from one medium to another is called refraction of light.

Human Eye

Human eye works like a camera and gives us the sense of vision.

Electricity

Flow of electric charge is called electric current.

Electromagnetism

Magnetic field is present around a current carrying conductor, and a magnet in electric field experiences a force due to electric field.

Source of Energy

An ideal source of energy should be ecnoomical, easy to carry, easy to store and should not produce too much waste.

Environment

The system of interdependency among living beings and non-living things is called ecosystem.

Natural Resources

We need to judiciously utilise natural resources because they are scarce.