What Is the Mole Concept of Class 11?


What is a Mole

In Class 11, the mole concept has been included for which it is very important to understand it in the best way. Mole is described as the quantity of any material that has the same number of fundamental components as a pure sample of 12C measuring precisely 12 g in terms of fundamental units. Mole is a Latin word that means “pile, heap, or assemblage.” The number of individuals that make up one mole was discovered to be 6.022 X 1023 in an experimentation, that is a characteristic known as an Avogadro’s constant (NA) or Avogadro’s number. This statistic is always expressed in per mole terms. Researchers may compare as well as debate very big numerical values using Avogadro’s number, which is important because ordinary things are made up of a vast number of molecules and atoms. Understanding the production of molecules, as well as their mixtures & interactions, requires an understanding of Avogadro’s number. Because one oxygen molecule will combine with two nitrogen atoms to generate a nitrous oxide molecule (N2O), a mole of oxygen (O) (6.022 X 1023 O atoms) will combine with two moles of nitrogen’s (2 6.022 1023 N atoms) to create a mole of N2O.

Molar Mass

A mole is a unit of measurement that lets us match the particles of a material towards its mass. The molecular weight, also known as molar mass, is the total of the mass among each as well as every atom in grammes that make up a mole of a molecule. Divide the specified mass of any material by the amount of that substance in g/mol to get the molar mass. Copper, for example, has an atomic weight of 63.546 amu or 63.546 g/mol. There is indeed a mole concept, or 6.022 X 1023 copper atoms, in this 63.546 g of copper. The fact that every element’s molar mass is simply its atomic mass calculated in g/mol is an essential aspect. It may also be calculated by multiplying the atomic mass provided in amu by the molar mass factor (1 g/mol). For example, the molar mass of the molecule CaCl2 may be calculated by adding the atomic masses of calcium (40.078 g/mol) as well as chlorine (2 X 35.45 g/mol), yielding a molar value of 110.98 g/mol.

Gram Molecular Mass and Gram Atomic Mass

A material’s gramme atomic mass is described as the amount of material in grammes whose numerical value is the same as the atomic mass of such a substance. This mass of a unit mole of an isotope appears to equal the gramme atomic mass. It may be calculated to use the material’s atomic weight from the periodic table and expressed in grammes. For example, iron (Fe) has a gramme atomic mass of 55.845 g due to its atomic weight of 55.845 u. As a result, each mole of iron atoms has a mass of 55.845 g.

Number of gram atoms=

Every substance’s gramme molecular mass is defined as the amount of material in grammes whose numerical value is equal to the molecular weights of that material. The mass of a unit mole of a molecular material in grammes is known as gramme molecular mass. It’s the same as molar mass. The main distinction is that the gramme molecular mass implies that the mass unit must be used. It might be expressed as grammes per mole or grammes (g). To compute the gramme molecular mass, we must first determine the molecular formula. Next, we must estimate the atomic masses of all the other components in the molecular formula. Then we must multiply the subscript following each element’s symbol, that denotes the number of atoms divided by their atomic masses. If the subscript is missing, the molecule must contain a single atom of an element. To acquire the needed gramme molecular mass, we must combine all of the numbers together. The gramme molecular mass of nitrogen, for instance, is 28 g rather than 28 u.

Number of gram molecules =

Do you know the answer of the below question?

Q.Classify the following as pure substances or mixtures. Separate the pure substances into elements, compounds and divide the mixtures into homogeneous and heterogeneous:

(i) Air

(ii) Milk

(iii) Graphite

(iv) Gasoline

(v) Diamond

(vi) Tap water

(vii) Distilled water

(viii) Oxygen

(ix) Brass

(x) 22 Carat gold

(xi) Steel

(xii) Iron

(xiii) Sodium chloride

(xiv) Iodised table salt

Gram Molecular Volume

Given typical circumstances of temperature (273 K) and pressure (1 atm), it is defined as the volume bound up by a mole of each gas (at STP). For any and all gases, the value was discovered to be 22.4 litres. It’s also known as molar volume, but it’s written as Vm.

1 mole of a gas = 1 Gram Molecular Mass

= 22.4 L (STP)

= 6.022 X 1023 molecules.

Every material’s molar volume may be obtained by dividing its molar mass by its own density.

Molar Volume=

M3 /mol is indeed the Standard unit of molar volume; in solids and fluids, it is cm3 /mol, and then for gases, it is dm3/mol. But what’s the significance of the idea of a mole? The mole concept pervades all aspects of chemistry. Because most quantitative chemical calculations are based on the mole, a grasp of the mole is essential for the study of chemistry.