Which of the following compounds does not produce chlorine gas upon heating?

When chlorine gas is passed through an aqueous solution of a potassium halide in the presence of chloroform,a violet colouration is obtained. On passing more of chlorine water,the violet colour disappears and the solution becomes colourless. This test confirms the presence of ........... in the aqueous solution.

In the following reaction,identify the nature of the product formed by the complete hydrolysis of $BrF_5$ at $R.T.$:
$BrF_5 + 3H_2O \longrightarrow HBrO_3 + 5HF$

The gas evolved on heating $CaF_2$ and $SiO_2$ with concentrated $H_2SO_4$,on hydrolysis gives a white gelatinous precipitate. The precipitate is

The incorrect statement is:

Fluorine reacts with water to produce