Given that $\Delta H_f(H) = 218 \ kJ/mol$,express the $H-H$ bond energy in $kcal/mol$.

In the following reaction,$A$ and $B$ respectively are:
$A$ $\xrightarrow{HBr} C_2H_5Br$ $\xrightarrow{B} A$

Area of the region enclosed between the curves $x = y^2 - 1$ and $x = |y| \sqrt{1 - y^2}$ is

The density of water at $20^oC$ is $0.998 \ g/cm^3$ and at $40^oC$ is $0.992 \ g/cm^3$. The mean coefficient of cubical expansion (in per ${}^oC$) is

Match the organism with its use in biotechnology.

$(a)$ Bacillus thuringiensis	$(i)$ Cloning vector
$(b)$ Thermus aquaticus	$(ii)$ Construction of first $rDNA$ molecule
$(c)$ Agrobacterium tumefaciens	$(iii)$ $DNA$ polymerase
$(d)$ Salmonella typhimurium	$(iv)$ Cry proteins

Select the correct option from the following:

The image of the point $(3, 8)$ in the line $x + 3y = 7$ is