(a) Among the given options: ∵FeSO4.7H2O is of light green colour. ∴FeSO4.7H2O is (A) (b) 3FeSO4.7H2O+ dil. 4HNO3─────▸Fe(NO3)3+Fe2(SO4)3+NO+23H2O The yellow solution is due to Fe(NO3)3. Note : In options, FeCl3 was given which was an error and thus, has replaced by Fe(NO3)3. (c) FeSO4.7H2O gives white ppt. with BaCl2. FeSO4.7KH2O+BaCl2─────▸FeCl2+BaSO4+7KH2O ∴(c) is (BaSO4) (d) When FeSO4.7H2O is heated, it looses its water and give brown mass of Fe2O3,SO2(g) and SO3(g) as follows. 2FeSO4
Δ
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Fe2O3(s)+SO2(g)+SO3(g) ∴(d) is (Fe2O3) ∴(b) is the correct option.