Inorganic Chemistry for IIT JAM: Topics to Study First
Which inorganic chemistry topics to study first for IIT JAM, with two worked practice questions and an eight-week study plan you can start this week.
This post tells you which inorganic topics to study first for IIT JAM Chemistry, and why.
You also get two worked practice questions and a study plan you can start this week.
Why inorganic chemistry needs a priority list
Inorganic chemistry feels like a pile of facts. Many students try to memorise all of it and give up halfway. That approach does not work.
Most inorganic facts come from a few ideas: how many electrons an atom has, how tightly the nucleus holds them, and how orbitals overlap or split in energy. Once you understand these ideas, many "facts" become predictions you can make yourself.
So study the topics that explain the most other topics first. Learn the isolated facts last.
The priority topics, in order
The table below is a teaching order, not an official weightage list. Check the current syllabus on the official IIT JAM website before you finalise your plan.
| Priority | Topic | What you should be able to do |
|---|---|---|
| 1 | Atomic structure and periodic properties | Compare size, ionisation enthalpy (energy to remove an electron), electron gain enthalpy and electronegativity, and explain the exceptions |
| 2 | Chemical bonding and molecular shape | Predict shapes from electron-pair repulsion, decide polarity, and use molecular orbital diagrams for diatomic species |
| 3 | Coordination chemistry | Name complexes, find isomers, apply crystal field theory and calculate magnetic moment |
| 4 | Main-group chemistry (s- and p-block) | Know group trends, the unusual behaviour of the first element of each group, and the structures of key compounds such as boranes and noble gas compounds |
| 5 | d-block and f-block elements | Explain variable oxidation states, colour, magnetic behaviour and the lanthanide contraction |
| 6 | Acids, bases and solvent systems | Use the hard and soft acid-base idea to predict stability and reactivity |
Topics 1 and 2 feed every other row. You cannot find the shape of a main-group compound without the electron-pair repulsion method, and you cannot split d-orbitals without knowing electron configurations.
The exam angle
IIT JAM asks you to apply a concept to a compound or ion you may not have seen before. A memorised line rarely helps. Prepare for these question types:
- Prediction questions: you are asked for the shape of a species, or which of two compounds is more acidic. You need a rule and a reason.
- Comparison questions: arrange a set in increasing order of some property. Exceptions matter here, so learn each one with its cause.
- Calculation questions: spin-only magnetic moment, crystal field stabilisation energy or oxidation state counting. These are short and score well if your method is clean.
- Statement-based questions: several statements are given and you pick the correct ones. Half-knowledge fails here, so know each fact together with its reason.
Practise different answer formats, including questions with more than one correct option and questions with a numerical answer. For every topic, ask yourself three things: what is the rule, what is the exception, and what is the reason?
Practice question 1: crystal field theory and magnetism
Both questions in this post are practice questions written for this article. They are not past-paper questions.
Question. Fe2+ forms two octahedral complexes: [Fe(H2O)6]2+ and [Fe(CN)6]4-. Find the number of unpaired electrons, the spin-only magnetic moment and the crystal field stabilisation energy of each. Give the energy in terms of ฮo, the octahedral splitting, and ignore the pairing energy.
Step 1: electron count. Iron has atomic number 26. Fe2+ has the configuration 3d6.
Step 2: field strength. Water is a weak-field ligand, so ฮo is smaller than the energy needed to pair electrons. Electrons spread out and the complex is high spin. Cyanide is a strong-field ligand, so ฮo is larger than the pairing energy. Electrons pair up in the lower set and the complex is low spin.
Step 3: fill the orbitals.
- [Fe(H2O)6]2+: t2g4 eg2. Four unpaired electrons.
- [Fe(CN)6]4-: t2g6 eg0. No unpaired electrons.
Step 4: magnetic moment. The spin-only formula is โ[n(n+2)] in units called BM, where n is the number of unpaired electrons. For n = 4, the value is โ24, about 4.9 BM. For n = 0, the value is zero, so the complex is diamagnetic (repelled weakly by a magnetic field).
Step 5: stabilisation energy. Each t2g electron contributes -0.4ฮo and each eg electron contributes +0.6ฮo.
- High spin: 4(-0.4) + 2(+0.6) = -0.4ฮo.
- Low spin: 6(-0.4) = -2.4ฮo.
Answer. The aqua complex has 4 unpaired electrons, a moment of about 4.9 BM and a stabilisation energy of -0.4ฮo. The cyano complex has no unpaired electrons, is diamagnetic and has -2.4ฮo. In a full treatment the low-spin case also carries a pairing cost, which is why you compare ฮo with the pairing energy first.
Why it matters. The same metal ion gives different magnetism with different ligands. Always decide the field strength before you fill the orbitals.
Practice question 2: shapes from electron-pair repulsion
Question. Predict the shape of XeF4 and ClF3. State the number of lone pairs on the central atom and say which molecule is polar.
Method. Count the valence electrons of the central atom, add one for each bonded atom, and divide by two to get electron pairs. The pairs arrange themselves to keep repulsion lowest. Lone pairs repel more strongly than bonding pairs, so they take the roomier positions.
XeF4. Xenon has 8 valence electrons. Four fluorine atoms add 4, giving 12 electrons, which is 6 pairs. Four pairs are bonding and two are lone pairs. Six pairs point to an octahedral arrangement. The two lone pairs sit opposite each other, which keeps their repulsion lowest. The four fluorine atoms lie in one plane, so the shape is square planar. The bond dipoles cancel, so the molecule is non-polar.
ClF3. Chlorine has 7 valence electrons. Three fluorine atoms add 3, giving 10 electrons, which is 5 pairs. Three pairs are bonding and two are lone pairs. Five pairs point to a trigonal bipyramidal arrangement. The lone pairs take equatorial positions, where they have fewer close neighbours at 90ยฐ. This leaves a T-shaped molecule. The dipoles do not cancel, so it is polar. The axial fluorines are bent slightly away from the lone pairs, so the F-Cl-F angle is a little less than 90ยฐ.
Answer. Both molecules have two lone pairs on the central atom. XeF4 is square planar and non-polar. ClF3 is T-shaped and polar.
Why it matters. Equal lone-pair counts do not mean equal shapes. The total number of electron pairs decides the starting geometry.
A study plan you can follow
Take about eight weeks if you are starting fresh, and adjust to your own exam date. ABC Chemistry runs a 6-month live online IIT-JAM batch that follows a similar order, and you can book a free demo class to see the teaching style first.
- Weeks 1-2: periodic properties and bonding. Write each trend and its exceptions on one page. Draw molecular orbital diagrams until you can do them without notes.
- Weeks 3-4: coordination chemistry. Learn nomenclature first, then isomerism, then crystal field theory. Do five magnetic moment and stabilisation energy calculations a day.
- Weeks 5-6: main-group chemistry. Study one group at a time. For each, note the unusual first member, the key compounds and their structures.
- Week 7: d-block, f-block and acid-base ideas. Link properties to electron configuration. Compare lanthanides with actinides.
- Week 8: mixed practice. Solve timed sets across all topics. Keep an error notebook and write the reason for every mistake.
Revise the error notebook every weekend. Repeated mistakes show you where a concept is still weak.
Key takeaways
- Study periodic properties, bonding and coordination chemistry first, because other topics depend on them.
- Learn every rule together with its exception and its reason.
- For complexes, decide the ligand field strength before filling d-orbitals.
- For shapes, count electron pairs first, then place the lone pairs.
- Finish with timed mixed practice and an error notebook.
Frequently asked questions
Should I memorise inorganic chemistry for IIT JAM?
Memorise only a small core, such as exceptions and standard structures. Understand the rest through electron configuration, orbital overlap and crystal field splitting. Those ideas let you work out answers during the exam.
Which inorganic topic should I start with?
Start with periodic properties and chemical bonding. They explain trends and shapes across the subject, and coordination chemistry becomes much easier after them.
How many questions should I practise each day?
Pick a number you can finish carefully. Solving a few questions and reviewing every error teaches more than rushing through many.
Where do I check the exact IIT JAM syllabus?
Use the official IIT JAM website for the current year. Syllabi change, so confirm the current session there before you finalise your plan.
