J.R. S. answered 09/23/21
Ph.D. University Professor with 10+ years Tutoring Experience
8 Na2MoO4 + 12 HCl + 4 BnEt3N+ Cl- ---> [BnEt3N]4 Mo8O26 + 16 NaCl + 6 H2O ... balanced equation
mmols Na2MoO4 = 1.2 mmol (÷8 ->0.15) = LIMITING REACTANT
mmols HCl = 2.0 mmol (÷12 -> 0.17)
mmols BnEt3N+ Cl- = 2.30 mmol (÷4 -> 0.58)
Theoretical yield = 1.2 mmol Na2MoO4 x 1 mmol [BnEt3N]4 Mo8O26 / 8 mmol Na2MoO4 = 0.15 mmol [BnEt3N]4 Mo8O26
To find the atom economy we look at the molar mass of the product divided by ∑ of molar masses of all the products. I'll leave it to you to find the molar masses of all the products, and then carry out this simple division:
MW [BnEt3N]4 Mo8O26 / MW NaCl + MW H2O + MW [BnEt3N]4 Mo8O26
e factor is calculated as mass of waste / mass of desired product
The mass of the waste will be mass of NaCl plus mass of H2O produced. You can calculate that from the 1.2 mmols Na2MoO4 and the stoichiometry of the balanced equation. The mass of the desired product, [BnEt3N]4 Mo8O26 will be 0.15 mmols x the molar mass of [BnEt3N]4 Mo8O26 in mg (not grams).
Good luck.