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Molar Mass Table

The weight of one mole of any chemical compounds is known as molar mass. Remember one mole of any substance contains 6.022 $\times$ 10$^{23}$ constituent particles. The chemical compounds whose molar mass range between 18 g/mol of water to hundreds of grams per mole for more complex chemical compounds can be determine in the chemistry laboratory. The lightest possible chemical compound is hydrogen gas, or $H_{2}$ and heaviest can consider as macromolecules. The molecular mass or molecular weight can be defined as the mass of one molecule of a substance. It is expressed in the unified atomic mass units (u) here one u is equal to 1/12th of the mass of one atom of carbon-12.  On the other hand molar mass or molar weight is the mass of one mole of a substance. Molar mass is usually expressed in g/mol. The mole is the standard method for communicating to express the quantity of a substance.

One mole of any elementary entities contains 6.022 $\times$ 10$^{23}$ constituent particles. 6.022 $\times$ 10$^{23}$ is Avogadro's number which is a constant. Hence we can say that one mole of donuts contains 6.022 $\times$ 10$^{23}$ donuts or 1mole of $H_{2}O$ contains 6.022 $\times$ 10$^{23}$ molecules or 1 mole of nails contains 6.022 $\times$ 10$^{23}$ nails or 1mole of Fe contains 6.022 $\times$ 10$^{23}$ atoms etc. So we can say that molar mass is the weight in grams of one mole which contains 6.022 $\times$ 10$^{23}$ entities. Hence a molar mass is the mass in grams of 6.022 $\times$ 10$^{23}$ entities.

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How to Find Molar Mass?

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The molar mass of a substance is the mass of one mole of its. It can say as the grams of substance found in one mole of the substance. The molar mass can be determined with the help of sum of the atomic masses of all constituent atoms. For example; the molar mass of $Al(NO_{3})_{3}$  will be equal to the total of masses of one Al atom, 3 N and 9 O atoms. It can be written as

(1 x 26.98) + (3 x 14.007) + (9 x 16.00) = 213.00 g/mol

Hence we can say that the molar mass of one mole of aluminum nitrate is 213.00 grams or 213.00 grams of aluminum nitrate contains 6.022 $\times$ 10$^{23}$ entities of $Al(NO_{3})_{3}$.

Molar Mass Table of Elements

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The atomic mass of an element helps to determine the molar mass of elements by looking the Periodic table such as the atomic mass of carbon is 12.01 hence it is equal to molar mass in g/mole. It will not applicable on diatomic elements like $O_{2}$, $N_{2}$, $H_{2}$ etc.  Some of the elements with their molar mass are listed below.

 Molar Mass (g/mol)   Element 
 Atomic Number 
 1.0079  H  1
 4.0026  He  2
 6.941  Li  3
 9.0122  Be  4
 10.811  B  5
 12.0107  C  6
 14.0067  N  7
 15.9994  O  8
 18.9984  F  9
 20.1797  Ne  10
 22.9897  Na  11
 24.305  Mg  12
 26.9815  Al  13
 28.0855  Si  14
 30.9738  P  15
 32.065  S  16
 35.453  Cl  17
 39.0983  K  18
 39.948  Ar  19
 40.078  Ca  20
 44.9559  Sc  21
 47.867  Ti  22
 50.9415  V  23
 51.9961  Cr  24
 54.938  Mn  25

Molar Mass Table of Compounds

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Some of the compounds with their molar mass are listed below.

  Chemical Compound  
 Molar Mass (gram/mol)  
 Ammonia ()  17
 Carbon Dioxide ()
 44
 Dichlorodifluoromethane  121
 Ethanol  46.1
 Hydrogen  2.02
 Nitrogen  28
 Oxygen  32
 Water  18

We know that a chemical compound is composed of more than more elements therefore the molar mass of a chemical compound will be sums of molar masses of all the constituent atoms of the compound.

Molar Mass of $NaCl$

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Sodium chloride is composed of one sodium atom and one chlorine atom. Therefore the molar masses of chemical compounds would be equal to the sums of the molar masses of all the atoms in one molecule. Hence molar mass of sodium chloride would be equal to the molar mass of one atom of sodium plus the molar mass of one atom of chlorine. 

(1 $\times$ 23 grams/mole Na) + (1 $\times$ 35.5 grams/mole Cl) = 58.5 grams/mole.

Molar Mass of $CaCl_{2}$

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In case of compounds with more than one similar atom, we have to multiply the atomic mass of that element with the number given in subscript. For example, the chemical formula of iron (II) chloride is  FeCl2 hence there are one atom of Fe and two atoms of Cl. Therefore the molar mass of compound would be;

(1 atom $\times$ 56 grams/mole Fe) + (2 atoms $\times$ 35.5 grams/mole of chlorine) = 127 grams/mole of $FeCl_{2}$

Similarly the molar mass of $CaCl_{2}$ would be;

(1 atom $\times$ 40.078 grams/mole Ca) + (2 atoms $\times$ 35.5 grams/mole of chlorine) = 111.078 g/mol of $CaCl_{2}$.

Molar Mass of $KCl$

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The potassium chloride is composed of one potassium atom and one chloride atom therefore the molar mass of potassium chloride would be equal to sum of atomic mass of one potassium atom and one chlorine atom. Hence the molar mass can be calculated as;

(1 atom $\times$ 39.09 g/mol K) + (2 atoms $\times$ 35.5 grams/mole of chlorine) = 110.09 g/mol of KCl.
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