Answer:
number of water molecules are 7
Explanation:
Mass of the hydrated salt = 4.93 g
Mass of the dehydrated salt = 2.41 g
Mass of water lost = 4.93 - 2.41 g = 2.52 g
The moles of the dehydrated salt is :
Amount = 2.41 g
Molar mass of
= 120 g/mol
The formula for the calculation of moles is shown below:
![moles = \frac{Mass\ taken}{Molar\ mass}](https://tex.z-dn.net/?f=moles%20%3D%20%5Cfrac%7BMass%5C%20taken%7D%7BMolar%5C%20mass%7D)
Thus, moles are:
![moles= \frac{2.41\ g}{120\ g/mol}](https://tex.z-dn.net/?f=moles%3D%20%5Cfrac%7B2.41%5C%20g%7D%7B120%5C%20g%2Fmol%7D)
![moles= 0.02\ mol](https://tex.z-dn.net/?f=moles%3D%200.02%5C%20mol)
The moles of water is :
Amount = 2.52 g
Molar mass of
= 18 g/mol
The formula for the calculation of moles is shown below:
![moles = \frac{Mass\ taken}{Molar\ mass}](https://tex.z-dn.net/?f=moles%20%3D%20%5Cfrac%7BMass%5C%20taken%7D%7BMolar%5C%20mass%7D)
Thus, moles are:
![moles= \frac{2.52\ g}{18\ g/mol}](https://tex.z-dn.net/?f=moles%3D%20%5Cfrac%7B2.52%5C%20g%7D%7B18%5C%20g%2Fmol%7D)
![moles= 0.14\ mol](https://tex.z-dn.net/?f=moles%3D%200.14%5C%20mol)
The simplest ration of the two are:
= 0.02 : 0.14 = 1 : 7
The formula is ![MgSO_4.7H_2O](https://tex.z-dn.net/?f=MgSO_4.7H_2O)
<u>So, number of water molecules are 7 </u>