Answer:
B
Step-by-step explanation:
Fe3O4(s) + CO(g) →FeO(s) + CO2(g)
Left side
Fe =3
O = 5
C = 1
Right side
Fe =1
O = 3
C = 1
Balance by finding common denominator
We'll make Fe 3 on the left side
Fe3O4(s) + CO(g) →3FeO(s) + CO2(g)
Left side
Fe =3
O = 5
C = 1
Right side
Fe =3
O = 5
C = 1