........ of a reaction cannot be determined experimentally.

Two circles whose radii are equal to $4$ and $8$ intersect at right angles. The length of their common chord is

The product of the lengths of the perpendiculars from any point on the hyperbola $x^2-y^2=8$ to its asymptotes is

$f(x) = e^x \sin x$, then $f^{(6)}(x)$ is equal to :

When zeolite is treated with hard water,the sodium ions are exchanged with

From a disc of radius $R$ and mass $M$,a circular hole of diameter $R$,whose rim passes through the centre is cut. What is the moment of inertia of the remaining part of the disc about a perpendicular axis,passing through the centre?