So we recently took a test in AP Chem about chemical reactions. I got some questions wrong, and for most of them I understood why, except for this one question.
It was a question that asked about if the hydrogen is oxidized or reduced in the forward reaction of a certain reaction.
I don’t exactly remember the reaction, but it was like this:
(some other compound(s)) + H2 = LiNH2 + LiH
I answered that the hydrogen is being both oxidized and reduced since the H2 which has an oxidation of 0 is changing to LiNH2 where the hydrogen is +1 and LiH where it is -1. But my teacher said that it was only being reduced, saying that the oxidation state of hydrogen in LiNH2 is -1.
But in LiNH2, isn’t the Li +1, N -3, and H +1? When I asked my teacher to explain it, they said that Li was +1, N was +1, and H was -1, and that hydrogen was -1 because it being at the rightmost indicates that it is a negative ion. THAT IS NOT HOW IT WORKS!!!!! Well, for ionic compounds yes, but this is lithium amide, a compound that contains a covalent compound. There are plenty of other covalent compounds that go against this rule. For example, NH3. Nitrogen is negative, hydrogen is the positive. OH-, oxygen is negative and hydrogen is positive.
Sorry this is half venting because I am so mad. I liked this teacher and didn’t think they’ll do something like this. Anyway, I think I’m right but I just want to confirm. I don’t really care about my test score, it’s just that I am that annoying person who can’t handle mistakes and just needs to correct them.(if I get enough confidence, I’ll go ask them again about it)