Lesson: Chapter 16 — Changes of Matter

16.2. Chemical equations 7 of 8 Reset answers

Clear all your answers?

This erases every answer in this set and starts you again at question one. Your score will be gone.

Type these four numbers to confirm:

Those numbers don't match. Look at them again and type them.

Yes, clear Keep them

Question 7

In the reaction Fe₂O₃ + 3CO → 2Fe + 3CO₂, what mass of iron is formed when 160 g of Fe₂O₃ is reduced? (Fe = 56)

A 160 g B 224 g C 112 g D 56 g

The right answer is the one marked above.

112 g. The equation gives two moles of iron, so 56 × 2 = 112 g.

56 g comes from ignoring the coefficient 2. A coefficient in a balanced equation gives the number of moles, so it must always be used as a multiplier.

Answer the question to continue.