If you are asked to classify the various algae into distinct groups,which of the following characters should you choose?

$A \rightarrow D$ is an endothermic reaction occurring in $3$ steps (elementary).
$(i)$ $A \rightarrow B$ $\Delta H_{i} = +ve$
$(ii)$ $B \rightarrow C$ $\Delta H_{ii} = -ve$
$(iii)$ $C \rightarrow D$ $\Delta H_{iii} = -ve$
Which of the following graphs between potential energy ($y$-axis) vs reaction coordinate ($x$-axis) correctly represents the reaction profile of $A \rightarrow D$?

The solution of $\frac{dx}{dy} + \frac{x}{y} = x^2$ is:

$A$ plane $\pi$ makes intercepts $3$ and $4$ respectively on the $z$-axis and $x$-axis. If $\pi$ is parallel to the $y$-axis,then its equation is:

$BF_3$ is used as a catalyst in many industrial processes because of its .....

$A$ ray of light passes through an equilateral prism such that the angle of incidence is equal to the angle of emergence and each one is equal to $3/4$th the angle of the prism. The angle of deviation is (in $^{\circ}$)