[Chemistry Class Notes] on Molarity Formula Pdf for Exam

In this section, the simplest definition and Molarity formula will be explained with proper examples. You will find out how this formula is derived and how it can be used in different ways. After studying this section, you will find it convenient to understand the Molarity definition and formula properly. It is an important term used in different chapters. Hence, learning this formula will become absolutely mandatory. There is no need to worry when you can find the easiest explanation of the equation of Molarity to eradicate all your doubts.

Easy Way to Define Molarity with Formula

There are different terms used in the advanced syllabus of Chemistry. NCERT Chemistry has a set of physical chemistry where you will find a lot of new terms included and explained in every chapter. These terms are sometimes interlinked and have close meanings too. One such common term introduced in the advanced level chemistry by NCERT is molarity. Along with this term, you will also learn what morality and normality are.

Molarity is a new term for students who have just entered the advanced segment of chemistry. Different types of units will be introduced in Physical Chemistry. These units are used to measure the concentration of solutions and different constituents of a mixture. They can also tell us how acidic or basic a solution is. To understand it properly, let us briefly discuss what the experts of have provided in this section of Molarity definition and formula.

According to the experts, molarity is defined as the concentration of solute in a solvent. You can refer to it as the easiest way to represent the concentration of a solute in a solution. To understand the actual definition of this term, you will have to understand what molecular weight is. The first step is to understand that the total weight of a molecule of a solute is called its molecular weight. The atomic weight of every constituent atom of the molecule is added to get the total weight of the solute’s molecule. When this molecular weight is expressed in grams, it represents one mole of that particular substance. This is what you have learned in your previous classes.

Let us recapitulate once more. One mole of a substance is the molecular weight of that substance expressed in grams. After learning what mole is, we can proceed to find out what the formula for Molarity is and how it is determined.

How Is the Correct Formula of Molarity Determined?

The correct formula of Molarity can only be determined when you know the proper definition of the term and the meaning of all the other chemical terms used to build the formula. As per the definition, the molarity of a solution is the total number of moles of solute present in a particular volume of solution.

If we represent everything with symbols then,

M = n/V

Here, ‘M’ stands for molarity, ‘n’ represents the number of moles of solute present in the solution and ‘V’ represents the volume of solution present in a container. Now that you have studied what mole stands for, you can easily calculate the amount of solute present in a particular solution. 

After learning the Molarity definition and formula, you should try some examples that show how molarity can vary and how it can be determined. These examples will also help you to find out other terms associated with the formula. In a nutshell, every problem related to molarity can be solved once you get familiar with the term and its formula.

Examples Used to Explain Molarity

The next section of this description page will take you to the explanation of examples. In this section, you will learn how the formula mentioned above can be used to calculate other associated terms. The explanation of the Molarity formula with examples will help you grab the concept better as the experts have used simple language.

Let us consider an example to keep this interesting discussion running. If one mole of calcium carbonate (CaCO3) is 100g. It means that the molecular weight of calcium carbonate is 100. Moving on, if this amount of calcium carbonate is present in 4 litres of a solution, then molarity will be:

M = n/V

=¼

=0.25 mol/litres

You can understand how this calculation using the formula of Molarity has been done. Do not forget to put on the unit of molarity after the calculation is done.If you consider another example to understand the Molarity ka formula, you will learn a new trick. There are different kinds of solutions you will study in advanced-level chemistry. When the solute and solvent are both liquids, do not forget to consider the resultant volume of the solution.

For instance, when 1 litre of sulphuric acid is mixed in 2 litres of water, the solution will become 3 litres. If you know what is the formula of Molarity, then you will understand that the volume of both liquids will be considered.

The use of the Molarity formula in Chemistry is exemplary. You will find it in different chapters of inorganic chemistry too. Hence, you should learn the definition and Molarity formula properly using the explanation given by the experts.

Concentration is a major criteria whenever carrying out different experiments in a laboratory. A German scientist termed the word MOLARITY in terms of concentration. Some other terms such Normality and molality were also termed in order to designate different concentrations. These concentration criterias helped out a lot while measuring a chemical in a laboratory.

Definition:

The concentration of the solution measured as the number of moles of a solute per liter of a solution is known as molar concentration or Molarity. It is denoted by the letter “M”.  The denotation is always in uppercase.

It is also defined as “Amount of substance of a solute per unit volume of solution.” 

Calculation of Molarity:

In order to calculate the Molarity of a solution, the following formula is widely used.

The formula for Molarity is [(M) = frac{n}{v}]

M denotes Molarity

n denotes the number of moles.

v denotes volume of the solution in liters. 

Calculation of number of moles of solute

[n = frac{text{Given mass}}{text{molecular mass}}] 

Sometimes, Molarity is denoted by the letter “c” . This time the denotation “c” is in lowercase. 

[c = frac{n}{v}] 

This can be also written as, 

[c = frac{N}{N_A V} ] 

Also, [c = frac{C}{N_A} ] 

The c denotes the molar  concentration  n is the amount of solute in moles  N is the number of constituent particle,  NA  is the Avogadro number which is equal to 6.022 140 76 × 1023 mol-1 .

The ratio of N/V  is denoted by C . 

Applications of Molarity:

Being a measuring Criteria, molarity is highly useful in so many fields . Some of the major applications of Molarity are enlisted:

• These are used by Chemist in order to measure or compare the concentration of solutions 

• In order to carry out a reaction, it is highly useful in measurement, so as to use the appropriate concentration while carrying out chemical reactions.

• These are highly used in pharmacy. Molarity gives the report of the laboratory values. For instance, it helps in analyzing blood samples.