True coelom appeared first in the course of evolution in

Let $\alpha, \beta$ be the roots of the equation $x^2-px+r=0$ and $\frac{\alpha}{2}, 2\beta$ be the roots of the equation $x^2-qx+r=0$. Then the value of $r$ is

The compound insoluble in acetic acid is

If $\int \frac{e^x-1}{e^x+1} d x=f(x)+c$,then $f(x)$ is equal to

$A$ disc of mass $M$ and radius $R$ is rolling with angular speed $\omega$ on a horizontal plane as shown. The magnitude of angular momentum of the disc about the origin $O$ is

The correct order of increasing $s$-character (in percentage) in the hybrid orbitals of the following molecules/ions is :-
$I.$ $CO_3^{2-}$
$II.$ $XeF_4$
$III.$ $I_3^-$
$IV.$ $NCl_3$
$V.$ $BeCl_2$