Fundamentals Chemistry part 1|9thClass|tutoronlines

Chapter No 1

Fundamentals of Chemistry( part 1)

Table of content:

Number of topics Name of topics
1 Chemistry
2 Branches of chemistry
3 Difference between every two different branches
4 Physical and Chemical properties
5 Empirical and molecular formula
6 matter
7 Molecular mass
8 Atomic number and Atomic mass
9 Valence
10 Oxidation state


This chapter is very important of chemistry. It is class 9th chapter of fundamental of chemistry. This is an Important short Question of this chapter and if you see it then you get a gain of your knowledge.

Short Question

Q.No.1. Define chemistry?

Ans. The branch of science which deals with the study of properties, structure and composition of matter.

Q.No.2. Define inorganic Chemistry?

Ans. I inorganic chemistry deals with study of all elements and their compounds except those compound which consist of carbon and hydrogen.

Q.No.3. Differentiate between organic and inorganic chemistry?
Ans. Organic chemistry:

The branch of chemistry which deals with the study of hydrocarbons and their derivation is called Organic chemistry.

Inorganic chemistry:

The branch of chemistry which deals with the all elements and their compounds except hydrocarbons.

Q.No.4. Differentiate Between Physical chemistry and biochemistry?
Ans. Physical chemistry:

The branch of chemistry which deals with the study of the Physical properties and Physical behaviour of material is called Physical chemistry.


The branch of chemistry which deals with the study of the Structure, composition and chemical reaction of substance found in living organism.

Q.No.5. Differentiate between industrial and analytical chemistry?
Ans. Industrial chemistry:

The branch of chemistry that deals with the study of the industrial processes and manufacturing of compounds at commercial scales.
Industrial chemistry deals with manufacturing of basic chemicals such as oxygen, chlorine, ammonia caustic soda, nitric acid and sulphuric acid, and use of there chemicals as a raw material for preparation of fertilizers, soap textile, agricultural products paints and papers etc.

Analytical chemistry:

The branch of chemistry which deals with the study of the analytical method to get the information about separation of analysis of a sample to identify its component.
The sample have been analysed by quality wise which help to identify the sample of chemistry.

Q.No.6. What is scope of biochemistry?

Ans. In biochemistry we study the chemical composition reaction and structure of material found in living organism. Biochemistry has application of food, science, medicines and agricultural fields.

Q.No.7. Define matter?

Ans. Any things that has mass and occupy space is called matter. e.g. our body and every thing surrounding us called matter

Q.No.8. Define Nuclear chemistry?

Ans. A branch of chemistry which deals with the study of radioactivity, nuclear reaction and properties of nuclear study is called nuclear chemistry.

Q.No.9. Define Environmental chemistry?

Ans. The branch of chemistry which deals with the study of component of environment and effect of human activities on environment is called environmental chemistry.

Q.No.10. For an element z=92 A=238. Calculate the number of electron and proton in it.

Ans. Number of proton = 92
Number of neutron = ?
proton of Number= z = 92
Number of neutron = A – Z
n = 238 – 92= 146

Q.No.11. Define relative atomic mass based on C12?

Ans. The relative atomic mass of an element is the average mass of atoms of that element as compared to 1/12th the mass of one atom of carbon 12. It is represented by amu. It is very small unit.

Q.No.12. Define empirical formula and molecular formula?
Ans. Empirical formula:

The simplest form of chemical formula is called empirical formula. It represents the minimum whole number ratio between the atoms of different elements.

Molecular formula:

The Formula which shows the actual number of atom of each element present in a molecule.

Q.No.13. Define atomic mass unit. why is it needed?

One atomic mass unit is 1/12 the mass of one atom of carbon 12. It is needed because, the size of atom is very small, so to find out the mass of such a small size atoms, this type of scale is required.

Q.No.14. What is the significance of the symbol of an element?

Ans. To write the elements with symbol, it become easy to write chemical reaction among them. The formula of such compound can also be written easily. By writing the full name it is easy to recognize different types of molecules. While it becomes hard to know the difference of different compounds of two element. For example hydro carbon contain hydrogen and carbon. By writing full name it would be difficult to find their difference.

Q.No.15. Soft drink is a mixture while water is compound. Give the reason?

Ans. Soft drink contain water, sugar, carbon dioxide colour and taste maker compounds, they do not under go chemical reaction of hydrogen and oxygen. So it is compound.
The constituent of soft drink has not fixed ratio. While water has ratio of its constituent.

Q.No.16. Differentiate between physical and chemical properties?
Ans. Physical properties:

The properties which are related with physical state of matter called physical properties e.g colour, smell, taste.

Chemical properties:

Chemical properties are related to chemical composition due to chemical changes. e.g. boiling point.

Q.No.17. Calculate the molecular mass of (HNO3)?

Ans. Atomic mass of H = 1amu
N of Atomic mass= 14 amu
Atomic mass of O = 16amu
molecular mass = (atomic mass of H) + ( atomic mass of N) + 3 ( atomic mass of O)
= 15+ 48= 63 amu

Q.No.18. What is the relationship between molecular formula and empirical formula?

Ans. Empirical formula shows simple whole number ratio of elements in a compound. While molecular formula shows the actual number of atoms of element of a compound.
for example empirical formula of benzene is CH and molecular formula C6H6.

Q.No.19. Define the mixture and give one example form daily life?

Ans. When two or more element mixed up physically without any fixed ratio, they form a mixture. e.g. Air

Q.No.20. Calculate the molecular mass of H2SO4?

Ans. H2= 2×1 , S=32 , O4= 16×4

Q.No.21. Write down the name of any two element which are in gaseous state?

Ans. Nitrogen and oxgen.

Q.No.22. What is the difference between valency and oxidation state?
Ans. Valency:

Them ability of atom to combine with other atom is called valency. Valency is always a whole number.

Oxidation state:

A number which represent the apparent charge on an atom, ion called oxidation state. It may be whole number or fraction.

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