Which of the following is the correct order of stability for alkali metal chlorides?

The potential difference between $A$ and $B$ in the figure is .............. $V$.

Standard entropy of $X_2, Y_2$ and $XY_3$ are $60, 40$ and $50 \, J \, K^{-1} \, mol^{-1}$,respectively. For the reaction,$\frac{1}{2} X_2 + \frac{3}{2} Y_2 \to XY_3, \Delta H = -30 \, kJ$,to be at equilibrium,the temperature will be .....$K$.

$A$ complete digestive system has

If the coordinate axes are the bisectors of the angles between the pair of lines $ax^2 + 2hxy + by^2 = 0$ where $h^2 > ab$ and $a \neq b$,then

If the coefficient of $x$ in the expansion of $\left(x^2+\frac{k}{x}\right)^5$ is $270$,then $k$ is equal to