Answer:
42g if CaO can be produced from 30g and 31.5g of CaO will be produced from 18g of O
Explanation:
40g of CA =56g
30g =×
cross multiple
=56*30/40
=42g
32g of O =56g
18g =×
cross multiple
=56*18/32
=31.5g
theoretical yield
42-31.5= 10.5
just guessing