Hi Samikhya...
In Fecl2, Fe has +2 valency whereas in Fecl3,Fe has +3 valency.
Iron (atomic weight 55.845) has an equivalent weight of 27.9225 in ferrous compounds (valence 2) and 18.615 in ferric compounds (valence 3).
Therfore the ratio is 1.5
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