FeS (Iron(Ii) Sulfide) Molar Mass

FeS (Iron(Ii) Sulfide) Molar Mass

Find the Molar Mass of Iron(Ii) Sulfide, FeS Step-by-Step

There are 4 easy steps to find the molar mass of FeS based on its chemical formula.

1. Count The Number of Each Atom

The first step to finding the molar mass of Iron(Ii) Sulfide is to count the number of each atom present in a single molecule using the chemical formula, FeS:
ElementNumber of Atoms
Fe (Iron)1
S (Sulphur/Sulfur)1

2. Find Atomic Mass of Each Element

Next, using the periodic table, find the atomic mass in g/mol of each element (the molar mass of an element is equal to its atomic mass):
Molar Mass (g/mol)
Fe (Iron)55.845
S (Sulphur/Sulfur)32.065

3. Compute Mass of Each Element

Multiply the number of atoms by the atomic weight of each element found in steps 1 and 2 to get the mass of each element in FeS:
Molar Mass (g/mol)
Fe (Iron)1 × 55.845 = 55.845
S (Sulphur/Sulfur)1 × 32.065 = 32.065

4. Sum Each Element's Mass

Finally, add together the total mass of each element to get the molar mass of FeS:
55.845 g/mol + 32.065 g/mol = 87.91 g/mol

5. Find Mole Fraction

To find the mole fraction and percentage of each element in FeS, divide each total from step 3 by the total molar mass found in step 4:
Mole FractionPercent
Fe (Iron)55.845 ÷ 87.91 = 0.635252× 100 = 63.5252%
S (Sulphur/Sulfur)32.065 ÷ 87.91 = 0.364748× 100 = 36.4748%

Molecular Weight of FeS

87.91 g/mol

The molar mass and molecular weight of FeS is 87.91.

Convert FeS From Moles to Grams

Moles mol

Convert FeS From Grams to Moles and Molecules

Weight g

Composition of Iron(Ii) Sulfide - FeS

Element Symbol Atomic Mass # of Atoms Mass Percent
Iron Fe 55.845 g/mol 1 63.5252%
Sulphur/Sulfur S 32.065 g/mol 1 36.4748%
Iron(Ii) Sulfide Element Mass PercentIron55.845gIron55.845gSulphur/Sulfur32.065gSulphur/Sulfur32.065g FeS # of AtomsIron1Iron1Sulphur/Sulfur1Sulphur/Sulfur1

Instructions

This program determines the molecular mass of a substance. Enter the molecular formula of the substance. It will calculate the total mass along with the elemental composition and mass of each element in the compound.

  • Use uppercase for the first character in the element and lowercase for the second character. Examples: Fe, Au, Co, Br, C, O, N, F.
  • You can use parenthesis () or brackets [].

Finding Molar Mass

Read our article on how to calculate molar mass.

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