# How to study (by heart) all the equations in inorganic chemistry? [closed]

Physical chemistry is easy to study as I have to just understand the concepts (like in physics) and apply some equations for calculations. In organic chemistry, reaction mechanisms helpsin remembering a lot of reactions and also doing conversion problems help a lot.

But, in the case of inorganic chemistry it is very difficult for me to remember those equations. My high school syllabus includes a lot of preparation methods of different compounds and reactions showing their chemical properties. But, unlike organic chemistry there is no problems based on it for deep understanding. So, what is actually needed is a good memory power. But, I'm not able to remember all those equations. So, how should I study them?

• Could you share some examples of problems you're dealing with? The inorganic chemistry course I took focused heavily on group theory and crystal structures, so I didn't see many of these "reactions" you're talking about. – chipbuster Nov 3 '13 at 8:54
• Every thing, how one knows all the equations in inorganic chemistry, comes from the experience.The time they have spent with that particular concept, asking one self, why one particular compound is prepared by a particular method, and why do they show such properties. Even the ssavec answer comes from his own experience with the concept. Anyone can't access one's experience, one should have little experience about what one is saying.I think the best answer for your question will be your's, which you get after experience. – Immortal Player Nov 4 '13 at 17:37
• @CURIE is one year enough for getting this experience? I'm a 12-grade high school student and every student in this level is wanted to remember lot of inorganic equations by heart including the temperature at which they are prepared(if provided in the text) for the final exam. – Rajath Krishna R Nov 6 '13 at 11:04
• @RajathKrishnaR.The student who reads one page for max hours, questioning and thinking even about simple concepts is the one who is more experienced, and has better memory in the manner that he feels speaking about complex concept, is as easy as explaining how to prepare coffee, initially learning seems to be slower, but swifts later by the earlier proper understanding he had. He can sit for hours, because of interest, he has, and the joy he gets from it. On the other hand, the student who reads max pages in one hour, is the least experienced one. – Immortal Player Nov 6 '13 at 11:47
• @VINAY , a 12th grader doesn't have that much time to spend because there are other subjects to study as well.. – Apurv Jan 13 '14 at 8:24

In organic chemistry, everything is based around C, H, O and N. Therefore to understand reactivity (somehow), there is just limited number of options.

In contrast, inorganic chemistry deals with the rest of periodic table, and each of the elements has its special properties. But there are general trends as well, but are more difficult to decipher and are often expressed by set of typical reactions, you should learn.

Usually they concern the stability of (oxidation) states, how to go from less stable to more stable one to obtain the desired compound and few processes how tho achieve the least stable state from the one found in nature.

It is difficult to state some simple rules, but there are several most typical anions and cations, and the chemistry of given element is just interactions with them. During the learning it helped me to have "all" the reactions (several hundreds) on a paper and for each one try to understand what happens and if there are others in the set, which are similar, and why. This helps you to spot the similarities. And - it is better to have more reactions then less, because then you have higher probability to spot the trends.

• Organic chemistry also deals with halide functional groups and fundctional groups with sulfur, phosphorus, and boron. – Caters Aug 9 '14 at 3:57

Let me tell you how I have managed to, with about 85-90% accuracy, been able to predict a large number of inorganic reactions. There are some prerequisites to do this. They are as follows:

1. The Periodic Table: You need to learn the stable oxidation states and configurations of ions. For instance, pretty much all sulphides, upon oxidation, become sulphates, because +6 is one of the most stable states of sulphur. Or, Ferrous and Ferric ions are pretty much equally stable, so much so that I like to call them toggler ions, as the switch between each other with ease.

2. Electrochemical Series: This is extremely important. It was simply amazing how much i could put into context after learning about this series. I could now understand why Iron metal produces hydrogen gas upon reacting with an acid. It will help you in countless redox reactions.

3. Solubility of compounds (in water) This will help you to predict precipitation reactions. In lower classes, we are taught these as lousy double displacement reactions, but they are actually pretty inaccurate. A ppt reaction will occur if the initial reactants are soluble, and at least one of the products is insoluble. Le-Chatelier's principle, if you will. Also, there is usually no way to predict solubility, as it is a complex interplay of hydration and lattice enthalpies, so you HAVE to memorize.

Now, a lot of reactions have no apparent logic, so there is no way to predict them. You will have to memorize these. For instance, in the Rasching's process to prepare hydrazine, Ammonia reacts with the hypochlorite ion to produce chloramine. This cannot be predicted with the above steps. It has to be memorized.

All I can say is, inorganic chemistry needs 55% memorization, and 45% common sense, which includes some intrinsic feeling as to what should be the outcome of a reaction, which will develop after a lot of practice.

Good Luck!

I had this problem too, and what helped me was remembering some of the preparation charachteristics for each group in periodic table, because the preparation of elements in a group is pretty much similiar. For example in 5th group, most elements are prepared from their most important alotropic modifications, more exact from their reduction with carbon. Example quartz $\ce{SiO2 + C ~ = ~Si + CO2}$ So does the $\ce{As}$ oxide, the $\ce{Bi}$ and the $\ce{Sb}$ oxide. Also $\ce{Pb}$ (4th) is prepared by its most important modification which is galenit $\ce{PbS}$.Concentrate in those similiarities in each group and you will have no trouble remembering them. If you don't find those similiarities i can help you.

I would suggest you to try and understand the equations and then learn them by heart. You can try and write them down when you are done reading them.Once written,you can actually go through it once in 2 days.This will further help you memorise the equations properly! Best of Luck!

• Memorising is a problem however tough we may try. In real life, one cannot go over inorganic reactions every two days. Besides, there are 100+ reactions and hectic trends (with exceptions too)! Your method might work for exam but what about after that? – Shuvam Shah Mar 7 '18 at 10:52