A Level Chemistry Redox Question Help

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xxccvc
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#1
Report Thread starter 2 weeks ago
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So I was recently going through a boardoworks presentation on redox reactions and it said that BaBr2 + H2S --> BaS + 2HBr was not a redox reaction.

But Br is oxidised (-2 to -1) and Hydrogen is reduced (+2 to +1)??

Can someone help please, is it redox or not??
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Wannabevetnurse
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Its not redox because there are two moles of HBr formed so the oxidation states of Hydrogen and Bromide remain the same throughout the reaction
BaBr2 (+2,-2) + H2S (+2,-2) ---> BaS (+2,-2) + 2HBr (+2,-2)
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xxccvc
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I understand the point of view you are coming from, however, in the previous slides of the presentation, they have the following example:



Cr2O72- + 14H+ + 6Li --> 2Cr3+ + 7H2O + 6Li+

Chromium is reduced because the oxidation number decreases from +6 to +3.

If you take into account the number of moles, chromium would not be reduced.
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xxccvc
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Actually, thanks I understand and realised what I was doing wrong.

Thanks!
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