2
$\begingroup$

In German problems olympiad 2014, the solution says that decomposition of arsine is not a redox reaction. Why would that be? Shouldn't H turn from -1 to 0 and As from 3+ to 0?

$$\ce{2AsH3 -> 2As + 3H2}$$

$\endgroup$
  • 2
    $\begingroup$ If they really said so, they probably implied that with electronegativity difference that small we may just as well consider both oxidation states 0 from the start, because they are arbitrary anyway. $\endgroup$ – Ivan Neretin Oct 5 '17 at 17:16
3
$\begingroup$

Often in chemistry "facts" depend on perspective. You're right that essentially H goes from -1 to 0 and As from 3+ to 0. But in general redox reaction involve two different chemical species. In this case it is better to think of the reaction as a decomposition reaction rather than a redox reaction.

$\endgroup$
  • $\begingroup$ Decomposition reactions are autoredox reaction (Disproportionation ).Are they not ? $\endgroup$ – Winston Cahya Oct 21 '17 at 5:48

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.