$23 \ g$ of $Na$ metal reacts with ethanol to produce which of the following?

$1\,kg$ of ice at $-10\,^{\circ}C$ is mixed with $4.4\,kg$ of water at $30\,^{\circ}C$. The final temperature of the mixture is ........ $^{\circ}C$ (specific heat of ice is $2100\,J/kg\cdot K$,latent heat of fusion of ice is $336000\,J/kg$,and specific heat of water is $4200\,J/kg\cdot K$).

Match the following molecules in Column-$I$ with the number of lone pairs on their central atom in Column-$II$.

Column-$I$ (Molecules)	Column-$II$ (Number of lone pairs on central atom)
$A$. $NH_3$	$1$. Two
$B$. $H_2O$	$2$. Three
$C$. $XeF_2$	$3$. Zero
$D$. $CH_4$	$4$. Four
	$5$. One

If $R$ is an equivalence relation on a set $A$,then $R^{-1}$ is

Which among the following complexes has square pyramidal geometry?

$e^{\log (\cosh^{-1} 2)}$ is equal to :