Respuesta :
Answer : Average molecular weight of group A = 104.0276 g
Average molecular weight of group B = 104.0920 g
Solution : Given, Moles of group A styrene = 5 moles
Moles of group A benzoyl peroxide = 0.0010 moles
Moles of group B styrene = 1.5 moles
Moles of group B benzoyl peroxide = 0.0010 moles
Molecular mass of styrene = 104 g/mole
Molecular mass of benzoyl peroxide = 242.23 g/mol
Formula used : Average molar mass = Total mass / Total moles
For group A,
Average molar mass of group A = [tex]\frac{\text{Total mass of group A}}{\text{Total moles of group A}}[/tex]
= [tex]\frac{\left ( 5\times 104 \right )+\left ( 0.0010\times 242.23 \right )}{5+0.0010}[/tex]
= [tex]\frac{520+0.24223}{5.0010}[/tex]
= [tex]\frac{520.24223}{5.0010}[/tex]
= 104.0276 g
Average molar mass of group A = 104.0276 g
For group B,
Average molar mass of group B = [tex]\frac{\text{Total mass of group B}}{\text{Total moles of group B}}[/tex]
= [tex]\frac{\left ( 1.5\times 104 \right )+\left ( 0.0010\times 242.23 \right )}{1.5+0.0010}[/tex]
= [tex]\frac{156+0.24223}{1.5010}[/tex]
= [tex]\frac{156.24223}{1.5010}[/tex]
= 104.0920 g
Average molar mass of group B = 104.0920 g
