<u>Answer:</u> The molar mass of
is 208.88 g/mol
<u>Explanation:</u>
To calculate the number of moles for given molarity, we use the equation:
![\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}](https://tex.z-dn.net/?f=%5Ctext%7BMolarity%20of%20the%20solution%7D%3D%5Cfrac%7B%5Ctext%7BMoles%20of%20solute%7D%7D%7B%5Ctext%7BVolume%20of%20solution%20%28in%20L%29%7D%7D)
Molarity of NaOH solution = 0.500 M
Volume of solution = 45.0 mL = 0.045 L (Conversion factor: 1 L = 1000 mL)
Putting values in above equation, we get:
![0.500M=\frac{\text{Moles of NaOH}}{0.045L}\\\\\text{Moles of NaOH}=(0.500mol/L\times 0.045L)=0.0225mol](https://tex.z-dn.net/?f=0.500M%3D%5Cfrac%7B%5Ctext%7BMoles%20of%20NaOH%7D%7D%7B0.045L%7D%5C%5C%5C%5C%5Ctext%7BMoles%20of%20NaOH%7D%3D%280.500mol%2FL%5Ctimes%200.045L%29%3D0.0225mol)
The chemical equation for the reaction of NaOH and
follows:
![2NaOH+H_2X\rightarrow Na_2X+2H_2O](https://tex.z-dn.net/?f=2NaOH%2BH_2X%5Crightarrow%20Na_2X%2B2H_2O)
By Stoichiometry of the reaction:
2 moles of NaOH reacts with 1 mole of ![H_2X](https://tex.z-dn.net/?f=H_2X)
So, 0.0225 moles of NaOH will react with =
of ![H_2X](https://tex.z-dn.net/?f=H_2X)
To calculate the number of moles, we use the equation:
![\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}](https://tex.z-dn.net/?f=%5Ctext%7BNumber%20of%20moles%7D%3D%5Cfrac%7B%5Ctext%7BGiven%20mass%7D%7D%7B%5Ctext%7BMolar%20mass%7D%7D)
Given mass of
= 2.35 g
Moles of
= 0.01125 moles
Putting values in above equation, we get:
![0.01125mol=\frac{2.35}{\text{Molar mass of }H_2X}\\\\\text{Molar mass of }H_2X=\frac{2.35g}{0.01125mol}=208.88g/mol](https://tex.z-dn.net/?f=0.01125mol%3D%5Cfrac%7B2.35%7D%7B%5Ctext%7BMolar%20mass%20of%20%7DH_2X%7D%5C%5C%5C%5C%5Ctext%7BMolar%20mass%20of%20%7DH_2X%3D%5Cfrac%7B2.35g%7D%7B0.01125mol%7D%3D208.88g%2Fmol)
Hence, the molar mass of
is 208.88 g/mol