The molecular weight of Potassium chloride (KCl) is 74.551.

Potassium chloride (KCl) is an inorganic compound of two elements: Potassium and Oxygen. The molecular weight of Potassium chloride (KCl) is 74.5483 which can be calculated by adding up the atomic weight of Potassium and Oxygen.

To calculate molecular weight of any compound, the first step is to know the constituent elements (atoms) and their number in that particular compound. Then calculate the total atomic weight of each element by multiplying its atomic weight by its number. The sum of total atomic weight of all constituent elements will be the molecular weight of the compound. Note that the value of atomic weight may differ slightly from different sources.

**CALCULATION PROCEDURE: Potassium Chloride (KCl) Molecular Weight Calculation**

**Step 1: Find out the chemical formula and determine constituent atoms and their number in a Potassium chloride molecule. **From the chemical formula, you will know different atoms and their number in a Potassium chloride molecule. Chemical formula of Potassium chloride is KCl. From the chemical formula of Potassium chloride, it is easy to find out that there are one Potassium (K) atom and one Chlorine (Cl) atom in a molecule of Potassium chloride.

**Step 2: Find out atomic weights of each atom (from periodic table). **

Atomic weight of Potassium (K): 39.0983 (Ref: Ciaaw-potassium)

Atomic weight of Chlorine (Cl): 35.4527 (Ref: Jlab-ele017)

**Step 3: Calculate the molecular weight of Potassium chloride by adding the total weight of all atoms. **

Number of Potassium atoms in Potassium chloride: 1

Atomic weight of Potassium: 39.0983

Total weight of Potassium atoms in Potassium chloride: 39.0983

Number of Chlorine atoms in Potassium chloride: 1

Atomic weight of Chlorine: 35.4527

Total weight of Chlorine atoms in Potassium chloride: 35.4527

**Step 4: Calculate the molecular weight of Potassium chloride by adding up the total weight of all atoms. **

Molecular weight of Potassium chloride (KCl): 39.0983 (Potassium) + 35.4527 (Chlorine)

So the molecular weight of Potassium chloride is 74.551.

Potassium Chloride (KCl) Molecular Weight Calculation

Molecular weight of Potassium chloride (KCl) | |||

Constituent atoms | Number of each atom | Atomic weight | Total weight |

K (Potassium) | 1 | 39.0983 | 39.0983 |

Cl (Chlorine) | 1 | 35.4527 | 35.4527 |

Molecular weight of Potassium chloride (KCl): | 74.551 |

## REFERENCES:

- Ciaaw-potassium : https://www.ciaaw.org/potassium.htm
- Jlab-ele017: https://education.jlab.org/itselemental/ele017.html