Question

how to calculate the molar mass of CO(NO3)2.6H20 ? Plz help

Answer 1

C=12, O=16, N=14, H=1
CO(NO3)2.6H2O
Molar mass = 12+16 + 2(14 + 3x16) + 6(1x2 + 16)
= 28 + 2(14 + 48) + 6(2 + 16)
= 28 + 2x62 + 6x18
= 28 + 24 + 108
= 160 g

Answer 2

To the calculation of the molar mass of $\mathrm{Co}\left(\mathrm{NO}_{3}\right)_{2} \cdot 6 \mathrm{H}_{2} \mathrm{O}$ we need to know the atomic weight of each element first.  

Atomic weights of each elements are as follows:

$\begin{array}{l}{\text { Molar mass of Co (Cobalt) }=58.93 \frac{g}{m o l}} \\ {\text { Molar mass of } \mathrm{N}(\text { Nitrogen })=14 \frac{g}{m o l}}\end{array}$

$\begin{array}{l}{\text { Molar mass of } \mathrm{H}(\text { Hydrogen })=1 \frac{g}{m o l}} \\ {\text { Molar mass of } \mathrm{O}(\text { Oxygen })=16 \frac{g}{m o l}}\end{array}$

Therefore molar weight of the given chemical compound is  

$\begin{array}{c}{=58.93+\{14+(16 \times 3)\} \times 2+6 \times\{(1 \times 2)+16\}} \\ {=58.93+124+108} \\ {=(58.93+(14+48) 2+6(2+16)} \\ {=58.93+124+108} \\ {=290.93 \frac{g}{m o l}}\end{array}$

Thus, the molar mass of $\mathrm{Co}\left(\mathrm{NO}_{3}\right)_{2} \cdot 6 \mathrm{H}_{2} \mathrm{O}$ is $=290.93 \frac{g}{m o l}$.