Question

Fe react with very dilute nitric acid to produce

Answer 1

Reacting iron powder with dilute nitric acid will produce Iron III Nitrate, nitrous oxide & water (the nitric acid oxidising the iron to the Fe3+ cation). The reaction proceeds slowly.

Fe + 4 HNO3 → Fe(NO3)3) + NO + 2H2O

Concentrated nitric acid renders the iron passive though - a small amount of Fe2O3 is formed and coats the metal, but that cannot be oxidised any further and the reaction then stops.

Answer 2

Answer:

4Fe + 10HNO3 = 4Fe(NO3)2 + NH4NO3 + 3H2O

Explanation:

The very dilute concentration of HNO3 gives the reduced product: NH4NO3, i.e when very dilute HNO3 reacts with nascent hydrogen it gives NH4NO3. So we proceed as:

1) Fe + 2HNO3 = Fe(NO3)2 + 2[H]

2) 8[H] + 2HNO3 = NH4NO3 + 3H20

Now, Adding 1 and 2 by multiplying 1 with 4 to cancel out the [H], we have:

4Fe + 10 HNO3 = 4Fe(NO3)2 + NH4NO3 + 3H20

I hope you understood.