Answer to Question #137452 in General Chemistry for marg

Question

Hg(l) + FeCl2(s)HgCl2(s) + Fe(s)......ΔH° = ?

Answer 1

We can estimate the ΔH° value of the given reaction by the (∆H°)i values of the following chemical reactions.

(1) Hg(l) + Cl2(g) ---> HgCl2(s)...... (ΔH°)1 = -224.3 kJ

(2) Fe(s) + Cl2(g) ----> FeCl2(s)......(ΔH°)2 = -341.8 kJ

Doing (1) – (2) we can estimate the required ∆H° value.

Hg(l) + Cl2(g) – Fe(s) – Cl2(g) ----> HgCl2(s) – FeCl2(s).....∆H° = (ΔH°)1 – (ΔH°)2

Or, Hg(l) + FeCl2(s) ----> HgCl2(s) + Fe(s) ∆H° = (-224.3+341.8) kJ

Or, Hg(l) + FeCl2(s) ----> HgCl2(s) + Fe(s)......ΔH° = 117.5 kJ

Hence, ΔH° = 117.5 kJ