Among the following ores Bauxite, Siderite, Cuprite, Calamine, Haematite, Kaolinite, Malachite, Magnetite, Sphalerite, Limonite, Cryolite, the number of principal ores if iron is _____________.
The oxidation state of manganese in the product obtained in a reaction of potassium permanganate and hydrogen peroxide in basic medium is ____________.
The number of molecule(s) or ion(s) from the following having non-planar structure is ____________.
$$\mathrm{NO}_{3}^{-}, \mathrm{H}_{2} \mathrm{O}_{2}, \mathrm{BF}_{3}, \mathrm{PCl}_{3}, \mathrm{XeF}_{4}, \mathrm{SF}_{4}, \mathrm{XeO}_{3}, \mathrm{PH}_{4}^{+}, \mathrm{SO}_{3},\left[\mathrm{Al}(\mathrm{OH})_{4}\right]^{-}$$
The spin only magnetic moment of the complex present in Fehling's reagent is __________ B.M. (Nearest integer).