Which of the following is not a mineral of fluorine?

$A$ mixture of concentrated $HCl$ and $HNO_3$ made in $3:1$ ratio contains:

Salt $+ MnO_2 \xrightarrow{\text{Conc. } H_2SO_4} X$ ($greenish yellow$ gas). Which of the following statements is incorrect?

Write a note on hydrogen halides. Explain the reactivity of halogens with oxygen. $OR$ Write a note on oxides of halogens.

When $I_2$ is passed through $KCl$,$KF$,and $KBr$ solutions,what happens?

Assertion : $SF_6$ cannot be hydrolysed but $SF_4$ can be.
Reason : $Six$ $F$ atoms in $SF_6$ prevent the attack of $H_2O$ on sulphur atom of $SF_6$.