Name the plant growth regulator which,when sprayed on sugarcane crops,increases the length of the stem and thus increases the yield of sugarcane.

Consider the following reaction,
$C_2H_5Cl + AgCN \xrightarrow{EtOH / H_2O} \underline{X} \text{ (major)}$
Which one of the following statements is true for $\underline{X}$?
$(I)$ It gives propionic acid on hydrolysis
$(II)$ It has an ester functional group
$(III)$ It has a nitrogen linked to ethyl carbon
$(IV)$ It has a cyanide group

If $\Delta = a^2 - (b - c)^2$ is the area of the $\triangle ABC$,then $\tan A$ is equal to

The number of lone pairs of electrons present on $Xe$ in $XeF_4$ is

Diborane reacts with ammonia under different conditions to give a variety of products. Which one among the following is not formed in these reactions?

Which of the following statements is correct for diamagnetic materials?