Some Basic Concept of Chemistry Nootan Solutions ISC Class-11 Ch-1

Some Basic Concept of Chemistry Nootan Solutions ISC Chemistry Class-11 Chapter-1 Review Numerical Questions . Step by step Solutions of Dr. HC Srisvastava ISC Chemistry Class-11 Nageen Prakashan Numerical Questions. Visit official Website CISCE for detail information about ISC Board Class-11 Chemistry

Some Basic Concept of Chemistry Nootan Solutions ISC Chemistry Class-11 Chapter-1 Numericsls


Class: 11
Subject: Chemistry
Chapter 1: Some Basic Concept of Chemistry

 

Board ISC
Writer  Dr. HC Srisvastava
Publications Nageen Prakashan
Book Name Nootan
Topics Solved review Numericals questions of page 3-96

 Matter

Anything which has mass and occupies space is called matter.

For example, book, pencil, water, air are composed of matter as we know that they have mass and they occupy space.

Classification of Matter

There are two ways of classifying the matter:

(i) Physical classification

(ii) Chemical classification

(i) Physical Classification:

Matter can exist in three physical states:

1. Solids 2. Liquids 3. Gases

1. Solids: The particles are held very close to each other in an orderly fashion and there is not much freedom of movement. Characteristics of solids: Solids have definite volume and definite shape.

2. Liquids: In liquids, the particles are close to each other but can move around. Characteristics of liquids: Liquids have definite volume but not definite shape.

3. Gases: In gases, the particles are far apart as compared to those present in solid or liquid states. Their movement is easy and fast.

Characteristics of Gases:

Gases have neither definite volume nor definite shape. They completely occupy the container in which they are placed.

(ii) Chemical Classification:

Based upon the composition, matter can be divided into two main types:

(a) Pure Substances

(b) Mixtures.

(a) Pure substances: A pure substance may be defined as a single substance (or matter) which cannot be separated by simple physical methods.
Pure substances can be further classified as (i) Elements (ii) Compounds

(b) Mixtures: The combination of two or more elements or compounds which are not chemically combined together and may also be present in any proportion, is called mixture. A few examples of mixtures are: milk, sea water, petrol, lime water, paint glass, cement, wood etc.

•Dalton’s Atomic Theory

In 1808, Dalton published ‘A New System of Chemical Philosophy’ in which he proposed the following:

1. Matter consists of indivisible atoms.

2. All the atoms of a given element have identical properties including identical mass. Atoms of different elements differ in mass.

3. Compounds are formed when atoms of different elements combine in a fixed ratio.

4. Chemical reactions involve reorganisation of atoms. These are neither created nor destroyed in a chemical reaction.

 Atomic Mass

The atomic mass of an element is the number of times an atom of that element is heavier than an atom of carbon taken as 12. It may be noted that the atomic masses as obtained above are the relative atomic masses and not the actual masses of the atoms. One atomic mass unit (amu) is equal to l/12th of the mass of an atom of carbon-12 isotope. It is also known as unified mass.

Average Atomic Mass

Most of the elements exist as isotopes which are different atoms of the same element with different mass numbers and the same atomic number. Therefore, the atomic mass of an element must be its average atomic mass and it may be defined as the average relative mass of an atom of an element as compared to the mass of carbon atoms (C-12) taken as 12w.

Uncertainty in Measurements

All scientific measurements involve certain degree of error or uncertainty. The errors which arise depend upon two factors.

(i) Skill and accuracy of the worker (ii) Limitations of measuring instruments.


Ch-1 Some Basic Concept of Chemistry Nootan ISC Chemistry Class-11  review Questions


Some Basic Concept of Chemistry Nootan Solutions 

ISC Chemistry Class-11 Chapter-1 Review Numerical Solutions

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