Hello Spoorti,

Some of the important topics for chemistry which have a high weightage are as follows:

LOW EFFORT REQ &HIGH WEIGHTAGE

• Atomic Structure
• Gaseous and Liquid States
• Electrochemistry
• Chemical kinetics
• Nuclear and Surface chemistry
• Chemical Bonding
• D-block elements
• Co-ordination compounds
• Alkyl halides 
• Aromatic Compounds

LOW EFFORT REQ & LOW WEIGHTAGE

• Chemical equlibrium
• Redox & volumetric analysis
• Solutions
• Metallurgy
• Qualitative analysis
• Hydrocarbons 

HIGH EFORT & HIGH WEIGHTAGE

• Thermodynamics
• P-block elements
• General organic chemistry
• Aledehydes and ketones
• Isomerism
• Carboxyllic acid and its derivatives

HIGH EFFORT & LOW WEIGHTAGE

• Mole concept
• Ionic equilibrium
• Solid State
• S-block element
• Periodic classification
• Classification and nomenclature
• Alcohol and ether
• Nitrogen compunds and aliphatic amines
• Biomolecules and polymers

Happy reading !All the best!

Hello Spoorti,

I would recommend you to go through our article on "JEE Main Chemistry Syllabus" for detailed syllabus of Chemistry (Physical, Organic and Inroganic Chemistry) from the link mentioned below.

Link: https://engineering.careers360.com/articles/jee-main-chemistry-syllabus

All the best!! 

Here is the section-wise important topics that you can study while preparing for Chemistry for JEE Main 2019

    Inorganic Chemistry- Classification of Elements and Periodicity in Properties, General Principles and Process of Isolation of Metals, Hydrogen, s - Block Elements (Alkali and Alkaline Earth Metals), Co-ordination Compounds, Environmental Chemistry to name few.

    Organic Chemistry- Purification and Characterisation of Organic Compounds, Some Basic Principles of Organic Chemistry, Hydrocarbons,Organic Compounds Containing Oxygen, Organic Compounds Containing Nitrogen, Bio Moleculesetc.

 Physical Chemistry- Some Basic concepts in Chemistry,States of Matter, Atomic Structure, Chemical Bonding and Molecular Structure,Chemical Thermodynamics, Equilibrium, Surface Chemistry,Chemical Kinetics and Redox Reactions and Electrochemistry.

The Weightage:

Organic Chemistry- 30%

Inorganic Chemistry- 30%

Physical Chemistry- 40%

Good Luck!