Molar mass,molecular mass and mole concept - Future Study Point

Molar mass,molecular mass and mole concept

Molecular mass

Molar mass, molecular mass and mole concept

The matter all around us are composed of atoms, the mass of the matter is one of the properties of the matter, it is the property which is determined by the some of the fundamental particles of the atom, the fundamental particles protons and neutrons are the contributor of the atomic mass, molecular mass or molar mass, although according to current theory protons and neutrons are also composed of quarks which is the smallest fundamental particle of the atom, so quarks are the basic contributors to add mass to atomic mass, molecular mass or molar mass.

Molecular mass


 Electrons are transformed from the leptons which is also known as basic fundamental particle but leptons are unstable particles,so quarks, electrons, and leptons are one of the basic fundamental particles, recently one more particle Hibbs boson is also discovered to have existed, according to latest theory this particle is the cause of the existence of the mass in the universe but here we are going to discuss atomic mass, molecular mass or molar mass on the basis of academic purposes for solving the questions based on mass, molecular mass or molar mass based on classical atomic theory.

Hibbs boson is an unstable particle and breaks down into the quarks. Hibbs boson is the generator of quarks which add mass to atomic mass, molecular mass or molar mass so scientist has called it God particle. All of these similar particles you can study in higher classes in particle physics theory. Here we shall study the theory based on the subject curriculum of middle-class students only.

molar mass

Before we study what is mole concept, molecular mass, molar mass, first we are required to study the atomic mass of an element.

You can also study

Atom, Molecule, and Atomicity

Determining Valency, Net Charge and Molecular Formula

Mole concept

Molar mass, molecular mass and mole concept

Atomic mass-

The number of protons in the nucleus is known as the atomic number which indicates the identity of an element because it is the total positive charge of the atom which is equal to the total number of negatively charged electrons. Electrons revolve around the nucleus almost with the speed of light so electrons do not contribute to adding mass to the atom. The protons and neutrons are called nucleons of the atoms, the mass of each single nucleons is known as 1 atomic mass unit, if total number of nucleons is 16 then the atomic mass is equal to the product of 16 and 1amu means 16 amu.

In short we can write amu to u.

Click for online shopping

Future Study Point.Deal: Cloths, Laptops, Computers, Mobiles, Shoes etc

Molecular mass-

The molecule is composed of similar or different atoms, so molecular mass is the sum of all the atoms in a molecule, as an example  Ca(OH)2

The molecular mass of Ca(OH)is

= number of Ca atoms × atomic mass of Ca + number of oxygen atoms × atomic mass of oxygen + number of hydrogen atom× atomic mass of hydrogen

Atomic mass of Ca =40 u,Atomic mass of O= 16 u,Atomic mass of H=1 u

The molecular mass of  Ca(OH)2 = 1×40 + 2× 16 +2×1=40 + 32 + 2 =74 amu

Hence the molecular mass of the Ca(OH)2  is 74 amu.

Molar mass, molecular mass and mole concept

See the video

Mole concept-

As 1 dozen of everything contain 12 things or 1 kg of identical things contain same number of thing on the same way the number of particles(atoms, molecules, ions, protons, neutrons, electrons, etc) in gram equivalent of atomic mass or molecular mass of the particular elements or compounds is fixed in STP(Standard Temperature and Pressure)  is fixed.

The Avagadro have evaluated the number of particles in 1 mole of a substance as 6.022×1023 which is known as Avogadro number or Avagadro constant, it is also known as particles in 1 mole of the substance.

Molar mass-

Gram equivalent of atomic mass or molecular mass of the particular elements or compounds is known as molar mass, its SI unit is gram. The molar mass of an element or compound contains 1 mole of substance which is equal to the Avogadro number.

The number of moles = Given mass/Molar mass = m/M

The number of particles(N) = (m/M)×N0

Where m =given mass, M = Molar mass, N0  = Avagadro number

Example- Determine the number of moles in 88 gm of  CO2.

Answer- The number of moles(n) =m/M, where m is given mass and M is the Molar mass of the substance.

Molecular mass of CO2 =12×1 + 16 × 2 = 44 amu

Molar mass (M) of CO2 = 44 gm

n = m/M =88/44 = 2

Therefore the number of moles in 88 gm are 2 mol.

Example- How many numbers of molecules of water available in 180 gm of water.

Answer. The molecular mass of H2O = 2× 1 + 16 ×1 = 18 u

Molar mass (M) of H2O  =  18 gm

The given maa(m) = 180 gm

N0  =6.022×1023 

The number of particles,N = (m/M)N0 

N = (180/18) ×6.022×1023 

N = 6.022×1024 

 Therefore the number of molecules of water in 180 gm of water is 6.022×1024 

Example. How many oxygen atoms are in 1.32 kg of carbon dioxide.

Answer. The molecular formula of carbon dioxide is CO2 

The molecular mass of CO2 = 12 × 1 + 16× 2= 44 u

The molar mass of carbon dioxide (M) = 44 gm

The given mass of carbon dioxide = 1.32 kg = 1320 gm

N =(1320/44)×6.022×1023 

N= 18.066×1023 

The number of molecules of carbon dioxide in 1.32 kg carbon dioxide are 18.066×1023 

In one molecule of carbon dioxide contain= 2 atoms of oxygen 

Number of oxygen atoms in 1.32 kg of carbon dioxide =2× 18.066×1023     

36.132×1023   ≈ 3.6 ×1023   

Study important questions for your cbse board exams 2020 with their solutions

Class 9 Physics Important Notes

What is the difference between Distance and Displacement

Difference between velocity and speed

Average Speed and Average velocity

Three equation of Motions

Three laws of motion

The second  law of motion

Recoil velocity of the gun

What is inertia?

Momentum: Definitions,units,formula and Uses in real life:Class 9 CBSE

The universal  law of gravitational force

What is the difference between mass and weight

Thrust and Pressure : Difference

Archimedes Principle: Complete detail

What is the difference between Work,Energy and Power: Class 9 CBSE

CBSE IX Class Science Sample Papers

Class 9 Chemistry Important Notes

Evaporation, Vapourization, and Latent heat

How does the water kept in an earthen pot become cold during summer?

What are the factors affecting evaporation?,

What is the difference between solution, colloid, and suspension?

What is the difference between the element and the compound?

Molar mass,molecular mass and mole concept

If energy is conserved then why do we need to save it for future generations?

Class 9 Biology Important Notes

Difference between Animal cell and Plant Cell

Difference between Smooth Endoplasmic Reticulum and Rough Endoplasmic Reticulum

Function and structure of Mitochondria

Class 9 Science Chapterwise NCERT Solutions and Important notes of Science

Structure and Function of Cell : Cell Biology

What are Chromosomes, DNA and Genes?

Types of plant tissues : Class 9 CBSE Notes

Animal Tissues : Class 9 Science CBSE

What is the green house effect?

E-books of physics,chemistry,biology ,maths and solutions of class 10 previous year’s question papers(click the link)

NCERT Solutions of Science and Maths for Class 9,10,11 and 12

NCERT Solutions for class 9 maths

Chapter 1- Number SystemChapter 9-Areas of parallelogram and triangles
Chapter 2-PolynomialChapter 10-Circles
Chapter 3- Coordinate GeometryChapter 11-Construction
Chapter 4- Linear equations in two variablesChapter 12-Heron’s Formula
Chapter 5- Introduction to Euclid’s GeometryChapter 13-Surface Areas and Volumes
Chapter 6-Lines and AnglesChapter 14-Statistics
Chapter 7-TrianglesChapter 15-Probability
Chapter 8- Quadrilateral

NCERT Solutions for class 9 science 

Chapter 1-Matter in our surroundingsChapter 9- Force and laws of motion
Chapter 2-Is matter around us pure?Chapter 10- Gravitation
Chapter3- Atoms and MoleculesChapter 11- Work and Energy
Chapter 4-Structure of the AtomChapter 12- Sound
Chapter 5-Fundamental unit of lifeChapter 13-Why do we fall ill ?
Chapter 6- TissuesChapter 14- Natural Resources
Chapter 7- Diversity in living organismChapter 15-Improvement in food resources
Chapter 8- MotionLast years question papers & sample papers

NCERT Solutions for class 10 maths

Chapter 1-Real numberChapter 9-Some application of Trigonometry
Chapter 2-PolynomialChapter 10-Circles
Chapter 3-Linear equationsChapter 11- Construction
Chapter 4- Quadratic equationsChapter 12-Area related to circle
Chapter 5-Arithmetic ProgressionChapter 13-Surface areas and Volume
Chapter 6-TriangleChapter 14-Statistics
Chapter 7- Co-ordinate geometryChapter 15-Probability
Chapter 8-Trigonometry

CBSE Class 10-Question paper of maths 2021 with solutions

CBSE Class 10-Half yearly question paper of maths 2020 with solutions

CBSE Class 10 -Question paper of maths 2020 with solutions

CBSE Class 10-Question paper of maths 2019 with solutions

NCERT Solutions for Class 10 Science

Chapter 1- Chemical reactions and equationsChapter 9- Heredity and Evolution
Chapter 2- Acid, Base and SaltChapter 10- Light reflection and refraction
Chapter 3- Metals and Non-MetalsChapter 11- Human eye and colorful world
Chapter 4- Carbon and its CompoundsChapter 12- Electricity
Chapter 5-Periodic classification of elementsChapter 13-Magnetic effect of electric current
Chapter 6- Life ProcessChapter 14-Sources of Energy
Chapter 7-Control and CoordinationChapter 15-Environment
Chapter 8- How do organisms reproduce?Chapter 16-Management of Natural Resources

NCERT Solutions for class 11 maths

Chapter 1-SetsChapter 9-Sequences and Series
Chapter 2- Relations and functionsChapter 10- Straight Lines
Chapter 3- TrigonometryChapter 11-Conic Sections
Chapter 4-Principle of mathematical inductionChapter 12-Introduction to three Dimensional Geometry
Chapter 5-Complex numbersChapter 13- Limits and Derivatives
Chapter 6- Linear InequalitiesChapter 14-Mathematical Reasoning
Chapter 7- Permutations and CombinationsChapter 15- Statistics
Chapter 8- Binomial Theorem Chapter 16- Probability

CBSE Class 11-Question paper of maths 2015

CBSE Class 11 – Second unit test of maths 2021 with solutions

NCERT Solutions for Class 11 Physics

Chapter 1- Physical World

chapter 3-Motion in a Straight Line

NCERT Solutions for Class 11 Chemistry

Chapter 1-Some basic concepts of chemistry

Chapter 2- Structure of Atom

NCERT Solutions for Class 11 Biology

Chapter 1 -Living World

NCERT solutions for class 12 maths

Chapter 1-Relations and FunctionsChapter 9-Differential Equations
Chapter 2-Inverse Trigonometric FunctionsChapter 10-Vector Algebra
Chapter 3-MatricesChapter 11 – Three Dimensional Geometry
Chapter 4-DeterminantsChapter 12-Linear Programming
Chapter 5- Continuity and DifferentiabilityChapter 13-Probability
Chapter 6- Application of DerivationCBSE Class 12- Question paper of maths 2021 with solutions
Chapter 7- Integrals
Chapter 8-Application of Integrals

Class 12 Solutions of Maths Latest Sample Paper Published by CBSE for 2021-22 Term 2

Class 12 Maths Important Questions-Application of Integrals

Class 12 Maths Important questions on Chapter 7 Integral with Solutions for term 2 CBSE Board 2021-22

Solutions of Class 12 Maths Question Paper of Preboard -2 Exam Term-2 CBSE Board 2021-22

Solutions of class 12  maths question paper 2021 preboard exam CBSE Solution











Scroll to Top