Calculate the Molecular Mass of Co(NO3)2. 6H2O

Answer: The molecular mass of Co(NO₃)₂. 6H₂O (Cobaltous Nitrate Hexahydrate) is 292 gm/mol.

• Molecular mass can be defined as the total mass of a given molecule. The unit of molecular mass is gram per mole (g/mol). In other words, we can say that molecular mass is the sum of the atomic masses of all the atoms that are present in the molecule. 
• We can calculate the molecular mass of any given molecule by just simply adding the atomic mass of the atom which is present in the given molecule. 
• To calculate the molecular mass of the given molecule i.e. Co(NO₃)₂. 6H₂O, follow the steps stated below:- 

1. We can find it out simply by just adding the atomic mass of copper (Cu) i.e. 60 and then we will add the atomic mass of nitrogen (N) i.e 14 and then multiply it by 2 as the two atoms of nitrogen are involved in the molecule.
2. And then we will add the atomic mass of 6 atoms of Oxygen i.e 16 and then we will also add the atomic mass of 6 molecules of water or the atomic mass of Hexa hydrates i.e by adding the atomic mass of 12 hydrogen atoms and atomic mass of 6 oxygen atoms. 
3. Another way of calculating the atomic mass of water is by just simply multiplying the number of water molecules that is present in the molecule as we already know that the atomic molar mass of water is 18. 
4. Finally, we will be able to find out the molecular mass of the given molecule i.e 292 gm/mole. In simple words, the sum of the molar mass of the anhydrous cobalt nitrate and the molar mass of the hexahydrate will result to be the molecular mass of the given molecule.