Which reagent is used to remove $SO_4^{2-}$ and $Cl^{-}$ ions from a solution?

If the angular velocity of a disc depends on the angle rotated $\theta$ as $\omega = \theta^2 + 2\theta$,then its angular acceleration $\alpha$ at $\theta = 1 \ rad$ is ......... $rad/sec^2$.

Two thin wire rings,each having a radius $R$,are placed at a distance $d$ apart with their axes coinciding. The charges on the two rings are $+q$ and $-q$. The potential difference between the centres of the two rings is

If the distance between the foci of an ellipse is $6$ and the length of the minor axis is $8$,then the eccentricity is

What are enzymes composed of?

Identify the chiral molecule from the following.