19 Aug

This is the  one questions that I have been asked by most of the students of IGCSE Chemistry.
What makes me feel sad is the fact that most students dread stoichiometry. In some cases, they are prepared to sacrifice the 7-8 marks on the questions based on stoichiometry and focus on other topics !!!
I believe that if we as teachers are able to understand the topic perfectly well ourselves and practice on the method of delivering the topic , taking different board exam questions and at the same time making a list of FAQ's that we think might be possibly asked by students in the class, then this will help to drive away the fear from the minds of 70-80% of our kids . When i say that , i do not intend to blame the teachers solely, as I myself am a teacher and know that we take a lot of efforts and there are other factors responsible for the understanding of the concepts. But i just explained the teacher's role here
Not going to the other factors that might affect the learning, here i give my students a few tips that  might make the learning a lot simpler:

1. Practice your mathematical skills  well, after-all  stoichiometry is based on calculations.

2.Next learn by heart the stoichiometry  formula. When i say this , I do not intend to tell you to put weightage on  only rote learning, but it is surely essential while solving sums. Secondly, even if your calculations go wrong, there is still the 100%  chance of getting marks for steps that involve the correct use of formulae.

3. Learn a single concept well and practice ample questions on it, so many questions that if you are given any more questions on it, there is no doubt that you will solve it correctly. This is when you must decide that it is the right time to move ahead to the next concept. Practice questions can be from your text book (Reference book) , but you MUST solve the  IGCSE chemistry Past Exam Papers for Paper 2/Paper4 and Paper 6 and match them with the marking schemes.

4. Once done studying all stoichiometry concepts in this way, you may then take random questions on complete stoichiometry to test your understanding.

This is not only the ideal way of mastering stoichiometry, but any other  topic from any other subject.

Now I shall give you some specific tips for mastering stoichiometry. The tips basically tell you the order in which you must learn the various subtopics:

1. Study thoroughly the  chemical names and formula of elements and compounds.

Step I : Study the definition of a mole . Infact study all the various formulae that will help you in calculating moles;


a)Avogadro number

b) Concentration formula

c) The molar gas volume formula

3. Moles= Mass/Mr formula.

Step 2: Study the   calculation of :

a) Percentage yield 

b) Percentage by mass

c) Percentage purity

I am saying to learn this together because the calculations are related and mastering them happens quicker.

Step 3: Learn to calculate limiting and excess reagents

Step 4:

a) Learn to calculate the molecular and empirical formula

Follow the above steps and there is no way , Stoichiometry  cannot be mastered. Infact I shall share with you the video  that i have on you tube that will help you master the complete stoichiometry in just 35 minutes.

Here is the you tube link:

Please leave your valuable comments dear students, so that I may know how to improve the blog content. remember your inputs are valuable because the ultimate aim is to make the learning easier for you. It only when you communicate that your problems can get solved.

Love you, Take care and stay blessed

* The email will not be published on the website.