H2(g) + 12(g) + 2H1(g)

Question

A student makes the following statements:
- Hydrogen always has the same oxidation number, so it has an oxidation number of +1 in both the reactant H2 and product Hi.
- Iodine is in Group VIlA, so it has an oxidation number of -1 in both the reactant 12 and
product HI.
- Neither hydrogen nor iodine changes oxidation states, so the reaction is not a redox reaction.

In three to five sentences, describe the mistake that the student made, and determine whether or not the reaction is a redox reaction. Explain your answer.

Answer 1

It would have been SOOOOOO much easier if you had written what you do (or don't) know about this.
First the equation is not written properly. It should be
H2(g) + I2(g) = 2HI(g) (Note the I and not 1. Note = sign not +)
H and I don't always have the same oxidation state. On the left H is 0 and so is I. On the right H is +1 and I is -1.
The fact that BOTH H and I changed oxidation state means it was a redox reaction.
Now you can put all of that into sentence form. I'm a chemist and not a writer.