Some Basic Concepts of Chemistry

Introduction

The involvement of chemistry in our daily lives is extensive, and the aspect that it touches couldn’t be explained easily. Due to its high involvement in almost everything, Chemistry is called ” the central science.” Chemistry acts as a bridge between other components of natural science and connects them. 

Application of Chemistry:

 The concept of chemistry is widely used in these fields- 

Agriculture and Food

• Chemistry is used in manufacturing urea, calcium phosphate, ammonium phosphate, etc. 
• It helps save the crops from pests and insects by using pesticides and insecticides.
• It is also used in manufacturing preservatives such as pickles, jam, butter, and more.

Medical and Sanitation

• The concept of chemistry is used in the manufacturing of drugs and medicines. For example, Cisplatin and Taxol are used in curing therapy. Along with it, AZT (Azidothymidine) is used to cure AIDS. 
• It is also used in the manufacturing of disinfectants which are used in the killing of microorganisms.
• The concept of chemistry is also used to sterilise water, which is done by adding a small amount of chlorine to it. 

Industrial Purposes

Chemistry has a wide application in the industry as well. It is used in manufacturing chemicals, acids, bases, salts, soaps, and a lot more. People widely use these items on a daily basis. 

Basic Concepts of Chemistry:

Matter

One can define matter as anything that occupies space. Therefore, those items have their mass as well. 

Example: Bottle, Ice, Water, etc. 

Types of Matter

Matter can be divided into two broad categories-

• Physical Classification
• Chemical Classification

Let us study the Physical Classification of Matter in detail. On the basis of physical properties, matter can be divided into-

• Solid: In the solids, the particles are bound very closely to each other, and they can’t move freely. The solids have a shape and volume. 

Examples of solids include Salt, Sugar, Plastic, etc. 

• Liquid: The particles are held together closely but have the freedom to move. However, liquids don’t have a fixed shape but have specific volumes. 

Examples of liquids include water, tea, solution, etc.

• Gas: The gas particles move freely and are held together very lightly. Gases neither have any shape nor volume. They gain the shape of the container they are poured into. 

Examples of gases include oxygen, carbon dioxide, etc. 

Let us understand the Chemical Classification of matter in a better way. 

Matter can be bifurcated based on chemical composition in two ways:

1. Pure Substances-
2. Mixtures-

Pure Substances

They are defined as any substance that can be distributed further and are generally a single substance. 

The two types of Pure Substance are-

1. a) Elements: They are made up of a single type of particle, which can either be an atom or a molecule. 

Examples of elements include sodium, oxygen, etc. 

They are further divided into Metals, Non Metals, and Semimetals. 

1. b) Compounds: Compounds are the combination of two or more elements mixed together in a definite proportion. 

Examples of compounds include H2O, CO, etc. 

They are divided into Organic and Inorganic Compounds. 

Mixtures

Mixtures are generally the combination of two or more elements present in indefinite proportions, generally not mixed together. 

The main types of mixtures are Heterogeneous Mixtures and Homogeneous Mixtures. 

1. Homogeneous Mixtures:

Homogeneous Mixtures have a uniform composition, and the elements cannot be separated out with simple methods.

For example, Sugar Solution has a uniform composition and is sweet throughout. 

1. Heterogeneous Mixtures: 

Heterogeneous Mixtures don’t have a uniform composition, and the elements can be separated out with simple methods. One can see the components of these mixtures with naked eyes.

For example, Cereals and Milk mixed together is a heterogeneous mixture. 

Properties of Matter

The properties of matter are classified into: 

1.Physical Properties

Physical Properties of matter are those properties that are measured without changing the composition of the substance. 

Some examples of Physical Properties are Colour, Boiling Point, and more. 

2.Chemical Properties

Chemical Properties are those properties that can be estimated only when a change in the substance’s chemical composition takes place. 

Some examples of Chemical Properties are the Acidity and Reactivity of a substance. 

Scientific Notation

One of the significant concepts of chemistry from the perspective of class 11 chemistry chapter 1 exam, Scientific Notation is basically a notion where the number is represented as 

N x 10n where,

n is an exponent that can have a positive or negative value and,

N is a digit term. 

One example is 46600000 = 4.66 x 107

SI Units System

The SI System or the International System of Units is a standard metric system used to take measurements. The SI system is made up of seven base units which are further used to derive 22 units. If you are preparing for class 11 chemistry chapter 1 exam, having a detailed and clear knowledge of SI Unit System becomes extremely crucial.

Laws of Chemical Conservation:

1.Law of Conservation of Mass: 

The law of conservation of mass was proposed by Antonie Lavoisier in 1789, which states, “mass can neither be created nor destroyed, it can only be transformed from one form to another.”

2.Law of Definite Proportions:

Proposed by Joseph Proust in 1799, this law is also known as the law of constant proportions. 

According to this law, all the chemical compounds will always have the same amount of elements by their mass. 

For example, there are various ways to form CO2. 

However, no matter what the method is, in C02, the ratio of Carbon and Oxygen’s weight is always in the ratio 3:8. 

3.Law of Multiple Proportions:

John Dalton proposed this law in 1804. This law says that when two elements combine and form more than one compound, the mass of one element combining with a fixed mass of another element will always be in the ratio of whole numbers. 

Let us understand with the help of an example; Carbon combines with oxygen to form CO and CO2. When comparing the cases, the mass of oxygen is in the ratio 1:2, which is a whole number. 

4.Law of Gaseous Volume (Gay Lussac’s Law): 

This law was proposed by Gay Lussac in 1808. It states that when the gases are kept at a particular pressure and temperature, the ratio of the reactants and products is a whole number. 

For example, combining one volume of Hydrogen gas with one volume of chlorine gives a two-volume HCL gas. 

5.Avogadro’s Law: 

Avogadro proposed this law in 1811. It states that the volume of gas molecules is directly proportional to the number of moles at a fixed temperature and pressure. 

It is represented as V ∝ n

where, 

V is the volume of gas molecules

n is the number of gas molecules 

V = kn,

Here, k is the proportionality constant. 

Conclusion

The involvement of chemistry in our daily lives is extensive, and the aspect that it touches couldn’t be explained easily. Due to its high involvement in almost everything, Chemistry is called ” the central science.” The SI System or the International System of Units is a standard metric system used to take measurements. The SI system is made up of seven base units which are further used to derive 22 units. Chemistry acts as a bridge between other components of natural science and connects them. Avogadro proposed this law in 1811. It states that the volume of gas molecules is directly proportional to the number of moles at a fixed temperature and pressure.