Picric acid is :

$$C{e^{ + 3}},\,\,L{a^{ + 3}},\,\,P{m^{ + 3}}\,\,$$ and $$Y{b^{ + 3}}\,\,$$ have ionic radial in the increasing order as

Oxidation number of Cl in CaOCl₂ (bleaching powder) is :

EMF of a cell in terms of reduction potential of its left and right electrodes is :