Which of the following hydrides is electron-deficient?

$XeO_4$ molecule is tetrahedral having

If tangents are drawn from any point on the circle $x^2+y^2=25$ to the ellipse $\frac{x^2}{16}+\frac{y^2}{9}=1$,then the angle between the tangents is

The $IUPAC$ name of the following compound is

Chloropicrin is obtained by the reaction of

The acute angle between the two lines whose direction ratios $(l, m, n)$ satisfy the equations $l+m-n=0$ and $l^2+m^2-n^2=0$ is