The number of Cl = O bonds in perchloric acid is, "________".

The elevation of boiling point of 0.10 m aqueous CrCl₃.xNH₃ solution is two times that of 0.05 m aqueous CaCl₂ solution. The value of x is ______.

[Assume 100% ionisation of the complex and CaCl₂, coordination number of Cr as 6, and that all NH₃ molecules are present inside the coordination sphere]

Potassium chlorate is prepared by the electrolysis of KCl in basic solution

6OH^- + Cl^- $$ \to $$ ClO₃^- + 3H₂O + 6e^-

If only 60% of the current is utilized in the reaction, the time (rounded to the nearest hour) required to produce 10 g of KClO₃ using a current of 2 A is_________.

(Given : F = 96,500 C mol^–1; molar mass of KCIO₃ = 122 g mol^–1)

In an estimation of bromine by Carius method, 1.6 g of an organic compound gave 1.88 g of AgBr. The mass percentage of bromine in the compound is _______.
(Atomic mass, Ag = 108, Br = 80 g mol^–1)