What are $X$ and $Y$ in the following reaction?
$CF_2Cl_2 \xrightarrow{UV} X + Y$

The process of the isolation of a metal by dissolving the ore in a suitable chemical reagent followed by precipitation of the metal by a more electropositive metal is called:

If $y=3x$ is a tangent to a circle with centre $(1,1)$,then the other tangent drawn through $(0,0)$ to the circle is

Considering ideal gas behavior, the expansion work done $(in kJ )$ when $144 g$ of water is electrolyzed completely under constant pressure at $300 K$ is $...$ .
Use: Universal gas constant $( R )=8.3 J K ^{-1} mol^{-1}$; Atomic mass $($in amu$)$: $H =1, O =16$

Two bodies of mass $4 ~kg$ and $5 ~kg$ are moving along east and north directions with velocities $5 ~m/s$ and $3 ~m/s$ respectively. The magnitude of the velocity of the centre of mass of the system is

Two polaroids are placed in the path of an unpolarized beam of intensity $I_0$ such that no light is emitted from the second polaroid. If a third polaroid,whose polarization axis makes an angle $\theta$ with the polarization axis of the first polaroid,is placed between these polaroids,then the intensity of light emerging from the last polaroid will be: