ini gimn cara nya tolong ya kak.

(1) 2 Fe + 3/2O2 => Fe2O3. ∆H = -840
(2) 2Al + 3/2O2 => Al2O3. ∆H = -1680

2Al + Fe2O3 => Al2O3 + 2Fe. ∆H.....????

jawab.
reaksi (1) dibalik, reaksi (2) tetap


(1) Fe2O3 => 2Fe + 3/2 O2 ∆H = + 840
(2) 2Al + 3/2O2 => Al2O3. ∆H = -1680
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2Al + Fe2O3 => Al2O3 + 2Fe ∆H = -840 kj/mol

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