Calculations of Molecular Weight

A material’s molecular Weight is necessary to notify us how many grams are in a mole of that chemical component. The mole is the standard unit of measurement in chemistry for determining how much of a material is present. The aggregate values of the atomic Weight of the atoms in specific chemical composition may be used to define molecular Weight.

The total atomic masses of all atoms within a molecule are calculated on a scale with Oxygen, carbon, hydrogen, and nitrogen atomic masses of 16, 12, 1, and 14, respectively. Water, for instance, has a total molecular weight of 18 (i.e., 2 + 16) because it contains two hydrogen atoms and one oxygen atom. Molecular Weight is also known as molecular mass.

The molecular Weight is the sum of all the atomic weights of all the atoms present in a specific molecular combination of a chemical compound. The molecular Weight of a single element is the sum of the atomic weights of the overall number of atoms of that element necessary to create a stable molecule. 

Calculations of Molecular Weight

The molecular Weight of a molecule is calculated using its molecular formula. In simple words, this means that the molecular Weight of a molecule is calculated by taking the product of each atom with its atomic number, after which a summation is taken for each Weight. 

How to Calculate Molecular Weight?

For instance, Hexane has the chemical formula C6H14. The subscripts list the number of each kind of atom in a molecule. Thus, each hexane molecule has 6 atoms of carbon and 14 atoms of hydrogen. A periodic table may be used to determine the atomic weights of carbon and hydrogen.

Now we know that the atomic Weight of carbon is 12, and the atomic Weight of hydrogen is 1. This means that:

Molecular Weight = (total number of atoms of 1 kind x atomic weight) + (total number of atoms of 2 kind x atomic weight) + (total number of atoms of 3 kind x atomic weight) and so on.

Thus, by formula, the molecular Weight of Hexane (C6H14) can be calculated as:

Molecular weight= (12 x 6) + (1 x 14) 

which is equal to (72 + 14), which gives 86. Therefore, the molecular Weight of one molecule of Hexane (C6H14) is 86.

Molecular Weight Calculation

The molecular Weight tells you how many grams of a chemical substance is contained in 1 mole of a chemical compound. In chemical processes and equations, the mole is used to calculate the stoichiometry of a particular molecule. The calculation of molecular Weight typically delivers the result in terms of amu or Da. The atomic mass unit is amu, while Da is represented by Dalton. Atomic Weight is determined in terms of the mass of the carbon isotope – 12, same is the case with molecular Weight. This isotope has a value of 12 amu and is hence considered standard. Molecular Weight aids in measuring the quantity of a chemical substance necessary for a specific chemical reaction.

When dealing with particular isotopes of an atom, consider the atomic Weight of that isotope in place of the weighted sum supplied by the periodic table. For example, if you only deal with the isotope deuterium instead of hydrogen, you would use 2.00 instead of 1.01 for the element’s atomic mass. Usually, the gap between an element’s atomic Weight and the atomic Weight of a particular isotope is minimal, but it might be significant in some computations!

Conclusion

The total of the atomic weights of the number of atoms in a chemical molecule is the molecule’s molecular Weight (MW). Although molecular Weight is commonly used, molecular mass is the more accurate term. A molecule is an entity made up of one or more distinct atoms held together by strong correlations.

There is a technical distinction between the two; molecular Weight and molecular mass are often used interchangeably in chemistry. The molecular weight unit is molecular mass, while molecular Weight is a unit of force that acts on the molecular mass. In chemistry, “relative molecular mass” is a more accurate phrase for molecular Weight and molecular mass.