The molecular weight of Beryllium chloride (BeCl_{2}) is 79.9175831.

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 weight of all constituent elements will be the molecular weight of the compound. Note that the value of atomic weight may differ from different sources.

**CALCULATION PROCEDURE**

**Step 1: Find out the chemical formula and determine constituent atoms and their number in a Beryllium chloride molecule. **From the chemical formula, you will know different atoms and their number in a Beryllium chloride molecule. Chemical formula of Beryllium chloride is BeCl

_{2}. From the chemical formula of Beryllium chloride, it is easy to find out that there are one Beryllium (Be) atom and two Chlorine (Cl) atoms in a molecule of Beryllium chloride.

**Step 2: Find out atomic weights of each atom. **

Atomic weight of Beryllium (Be): 9.0121831 (Ref: Pubchem-4, Jlab-ele004)

Atomic weight of chlorine (Cl) : 35.4527 (Ref: Pubchem-Chlorine, jlab-ele017)

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

Number of Beryllium atoms in Beryllium chloride: 1

Atomic weight of Beryllium: 9.0121831

Total weight of Beryllium atoms in Beryllium chloride: 9.0121831 x 1 = 9.0121831

Number of chlorine atoms in Beryllium chloride: 2

Atomic weight of chlorine: 35.4527

Total weight of chlorine atoms in Beryllium chloride: 35.4527 x 2 = 70.9052

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

Molecular weight of Beryllium chloride (BeCl_{2}):

9.0121831 (Beryllium) + 70.90 (Chlorine)

So the molecular weight of Beryllium chloride is 79.9175831.

Molecular weight of Beryllium chloride (BeCl_{2}) | |||

Atoms (elements) in Beryllium chloride | Number of each atom in Beryllium chloride | Atomic weight | Total weight |

Be (Beryllium) | 1 | 9.0121831 | 9.0121831 (9.0121831 x 1) |

Cl (Chlorine) | 2 | 35.4527 | 70.9052 (35.4527 x 2) |

Molecular weight of Beryllium chloride (BeCl_{2}): | 79.9175831 |

## REFERENCES:

- Pubchem-4: https://pubchem.ncbi.nlm.nih.gov/element/4
- Jlab-ele004: https://education.jlab.org/itselemental/ele004.html
- Pubchem-Chlorine: https://pubchem.ncbi.nlm.nih.gov/element/Chlorine
- jlab-ele017: https://education.jlab.org/itselemental/ele017.html