Respuesta :

R0kia

Answer:

2nd and last.

Explanation:

In the first equation,the number of hydrogen atoms is not balanced and in the third,the number of aluminum atoms is not balanced.

evamoreno244466666

Answer:

1. Fe 2 O 3 + 3H 2 2Fe + 3H 2 O

2. CaCO 3 CaO + CO 2