What is $X$ in the following reaction?
$MgCl_2 + 2H_2O \to X + 2HCl + H_2$

If $2x + 3y + 12 = 0$ and $x - y + 4\lambda = 0$ are conjugate with respect to the parabola $y^2 = 8x$,then $\lambda$ is equal to

What are $\underline{A}, \underline{B}, \underline{C}$ in the following reactions?
$(I)$ $(CH_3 CO_2)_2 Ca \xrightarrow{\Delta} \underline{A}$
$(II)$ $CH_3 CO_2 H \xrightarrow[Red\ P]{HI} \underline{B}$
$(III)$ $2 CH_3 CO_2 H \xrightarrow{P_4 O_{10}} \underline{C}$
$\underline{A} \quad \underline{B} \quad \underline{C}$

$A$ force of $(3\hat i + 4\hat j)\, N$ acts on a body and displaces it by $(3\hat i + 4\hat j)\, m$. The work done by the force is ............. $J$.

Given below are $2$ statements:
Statement $I$: The number of species among $BF_4^-$, $SiF_4$, $XeF_4$ and $SF_4$, that have unequal $E-F$ bond lengths is $2$. Here, $E$ is the central atom.
Statement $II$: Among $O_2^-$, $O_2^{2-}$, $F_2$ and $O_2^+$, $O_2^-$ has the highest bond order.
In the light of the above statements, choose the correct answer from the options given below

Which of the following substances is obtained from the fungus $Claviceps$ $\text{purpurea}$ (ergot)?