Answer to Question #348425 in General Chemistry for Austine

Question

1. Iodic acid, HIO3, can be prepared by reacting iodine, I2, with concentrated nitric

acid. The skeleton equation is:

I2(s) + NO3

-

(aq) → IO3

-

(aq) + NO2(g). Balance this equation using the half reaction method.

Answer 1

I₂ + HNO₃ = HIO₃ + NO₂ + H₂O

On top of each element, we write the degree of oxidation:

I₂⁰ + [N⁵⁺O₃^2-]^- = [I⁵⁺O₃^2-]^- + N⁴⁺O₂^2-

We write down the elements whose oxidation state has changed and determine how many electrons they have received or donated:

I₂ - 10 e^- => 2 I⁵⁺

N⁵⁺ + e^- => N⁴⁺

We write the number of electrons given by I2 in front of N5 + and the number of electrons received by N5 + in front of I2 as a coefficient.

Answer:

I₂ + 10 HNO₃ = 2 HIO₃ + 10 NO₂ + 4H₂O