Question

Iron can be obtained by reduction of iron oxide $(Fe_{3}O_{4})$ with $CO$ according to the reaction: $Fe_{3}O_{4} + 4CO \to3Fe +4CO_{2}$ How many kg of $Fe_{3}O_{4}$ should be heated with $CO$ to get $3\, kg$ of iron?

• A. $8.12\,g$
• B. $4.14\,g$
• C. $6.94\,g$
• D. $16.8\,g$

Answer 1

Answer: (B)

$4.14\,g$

Answer 2

\underset{\text{232,g}}{ {Fe3O4}} $+ 4CO$ ${->}$ \underset{\text{56\times$3=168$,g }}{3Fe} $+4CO_{2}$ $3$ moles of $Fe$ is produced from $1$ mole of $Fe_{3}O_{4}$ $168\, g$ of $Fe$ is produced from $232\, g$ of $Fe_{3}O_{4}$ $3\, kg$ of $Fe$ will be produced from $\frac{232}{168} \times 3000\,g$ $=4142.8\, g$ or $4.14\,kg$ of $Fe _{3}O_{4}$