Question

Fe + HNO3(конц) ---->

Answer 1

Fe+6HNO3(конц.) = Fe(NO3)3+3NO2+3H2O

Answer 2

C + 4HNO3(конц. , гор. ) = CO2↑ + 4NO2↑ + 2H2O
3Ag + 4HNO3(разб. ) = 3AgNO3 + NO↑ + 2H2O
Fe + 4HNO3(разб. ) = Fe(NO3)3 + NO↑ + 2H2O или 5Fe + 12HNO3(оч. разб. ) = 5Fe(NO3)2 + N2↑ + 6H2O
Fe + 6HNO3(конц. ) = Fe(NO3)3 + 3NO2↑ + 3H2O 

Answer 3

Balancing the Equation:

The given chemical equation is Fe + HNO3 (conc) → ?. To balance this equation, we need to ensure that the number of atoms on both sides of the equation is equal.

The balanced equation for the reaction between Fe and HNO3 (conc) is:

3Fe + 4HNO3 (conc) → 3Fe(NO3)2 + 2NO + 2H2O.

Explanation:

In the balanced equation, we have 3 iron (Fe) atoms on the left side and 3 iron (Fe) atoms on the right side. Similarly, we have 12 hydrogen (H) atoms and 12 oxygen (O) atoms on both sides of the equation.

On the left side, we have 4 nitric acid (HNO3) molecules, which contain a total of 4 nitrogen (N) atoms, 12 hydrogen (H) atoms, and 12 oxygen (O) atoms. On the right side, we have 3 iron(II) nitrate (Fe(NO3)2) molecules, which contain a total of 6 nitrogen (N) atoms, 18 oxygen (O) atoms, and 6 iron (Fe) atoms.

Additionally, we have 2 nitrogen monoxide (NO) molecules and 2 water (H2O) molecules on the right side of the equation.

Redox Reaction:

The reaction between Fe and HNO3 (conc) is a redox reaction. In this reaction, iron (Fe) is oxidized, and nitric acid (HNO3) is reduced.

The oxidation half-reaction is:

3Fe → 3Fe^3+ + 3e^-.

The reduction half-reaction is:

4HNO3 + 3e^- → 2NO + 2H2O + 4NO3^-.

Standard Electrode Potential:

The standard electrode potential (E0) of the reaction can be used to determine the spontaneity of the reaction. The standard electrode potential for the reduction half-reaction of nitric acid (HNO3) is +0.77 V.

Gibbs Free Energy:

The Gibbs free energy change (ΔG) for the reaction can be calculated using the standard electrode potential (E0) and the equation:

ΔG = -nFE0,

where ΔG is the Gibbs free energy change, n is the number of moles of electrons transferred, F is the Faraday constant (96485 C/mol), and E0 is the standard electrode potential.

The negative value of ΔG indicates that the reaction is spontaneous.

Conclusion:

The balanced equation for the reaction between Fe and HNO3 (conc) is:

3Fe + 4HNO3 (conc) → 3Fe(NO3)2 + 2NO + 2H2O.

This is a redox reaction where iron (Fe) is oxidized and nitric acid (HNO3) is reduced. The standard electrode potential for the reduction half-reaction of nitric acid is +0.77 V. The negative value of the Gibbs free energy change (ΔG) indicates that the reaction is spontaneous.

Please let me know if you need any further clarification or have any additional questions!