The molecular weight of Arsenic pentoxide [As_{2}O_{5}] is 229.84019.

Arsenic pentoxide [As_{2}O_{5}] is an inorganic compound of two elements: Arsenic (As) and Oxygen (O). The molecular weight of Arsenic pentoxide is 229.84019 which can be calculated by adding up the total weight (atomic weight multiplied by their number) of all its elements.

**CALCULATION PROCEDURE: Arsenic pentoxide [As**_{2}O_{5}] Molecular Weight Calculation

_{2}O

_{5}] Molecular Weight Calculation

**Step 1: Find out the chemical formula and determine constituent atoms and their number in an Arsenic pentoxide molecule. **From the chemical formula, you will know different atoms and their number in an Arsenic pentoxide molecule. The chemical formula of Arsenic pentoxide is As

_{2}O

_{5}. From the chemical formula, you can find that one molecule of Arsenic pentoxide consists of two Arsenic (As) atoms and five Oxygen (O) atoms.

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

Atomic weight of Arsenic (As): 74.921595 (Ref: Jlab-ele033, ciaaw-arsenic)

Atomic weight of Oxygen (O): 15.9994 (Ref: Jlab-ele008)

**Step 3: Calculate the molecular weight of Arsenic pentoxide by adding the total weight of all atoms. **

Number of Arsenic (As) atoms in Arsenic pentoxide: 2

Atomic weight of Arsenic: 74.921595

Total weight of Arsenic atoms in Arsenic pentoxide: 74.921595 x 2 = 149.84319

Number of Oxygen (O) atoms in Arsenic pentoxide: 5

Atomic weight of Oxygen: 15.9994

Total weight of Oxygen atoms in Arsenic pentoxide: 15.9994 x 5 = 79.997

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

Molecular weight of Arsenic pentoxide: 149.84319 (Arsenic) + 79.997 (Oxygen) = 229.84019

So the molecular weight of Arsenic pentoxide is 229.84019.

**Arsenic pentoxide [As _{2}O_{5}] Molecular Weight Calculation**

Molecular weight of Arsenic pentoxide [As_{2}O_{5}] | |||

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

Arsenic (As) | 2 | 74.921595 | 149.84319 |

Oxygen (O) | 5 | 15.9994 | 79.997 |

Molecular weight of Arsenic pentoxide [As_{2}O_{5}]: | 229.84019 |

## REFERENCES:

- Jlab-ele033: https://education.jlab.org/itselemental/ele033.html
- ciaaw-arsenic: https://www.ciaaw.org/arsenic.htm
- Jlab-ele008: https://education.jlab.org/itselemental/ele008.html

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