The equation of the tangent at $(-4, -4)$ on the curve $x^2 = -4y$ is

At $T \text{ K}$,the ratio of kinetic energies of $4 \text{ g}$ of $H_{2(g)}$ and $8 \text{ g}$ of $O_{2(g)}$ is

The equilibrium constant for the given reaction is $100$.
$N_{2(g)} + 2 O_{2(g)} \rightleftharpoons 2 NO_{2(g)}$
What is the equilibrium constant for the reaction given below?
$NO_{2(g)} \rightleftharpoons \frac{1}{2} N_{2(g)} + O_{2(g)}$

Consider the following statements about Langmuir isotherm.
$I.$ The free gas and adsorbed gas are in dynamic equilibrium.
$II.$ All adsorption sites are equivalent.
$III.$ The initially adsorbed layer can act as a substrate for further adsorption.
$IV.$ The ability of a molecule to get adsorbed at a given site is independent of the occupation of neighboring sites.
The correct statements are

If the temperature of the sun were to increase from $T$ to $2T$ and its radius from $R$ to $2R$,then the ratio of the radiant energy received on Earth to what it was previously will be

Companion cells are closely associated with $..........$.