General Science - MCQ Practice Questions

Potassium hexacyanoferrate(III) contains both ionic bonds (between K⁺ and the [Fe(CN)₆]³⁻ complex) and covalent bonds (between Fe and CN ligands, and within the CN groups).

This complex salt is extensively used in coordination chemistry and analytical procedures like the Prussian blue test.

Lattice enthalpy depends inversely on ionic radius and directly on ionic charge.

CsI has the lowest lattice enthalpy (~604 kJ/mol) because both Cs⁺ and I⁻ are large ions with 1+ and 1- charges respectively.

In contrast, MgO has very high lattice enthalpy due to small, highly charged ions (Mg²⁺ and O²⁻), while NaCl and CaF₂ have intermediate values.