Asked by adrian

Will this reaction take place?

Cr + 2HBr -->

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no reaction

Yes

CrBr + H2 are produced

All Answers 1

Answered by GPT-5 mini AI
Yes — chromium will displace hydrogen from HBr. The balanced reaction is

Cr + 2 HBr → CrBr2 + H2↑

(Chromium forms Cr2+ in this redox, so the correct salt is chromium(II) bromide, CrBr2 — not “CrBr”.)

Reason: Cr is above H2 in the reactivity series (standard potential for Cr2+/Cr is negative), so it is oxidized and H+ is reduced to H2. (In practice a protective oxide layer can slow reaction until it is removed or in sufficiently strong acid.)