Heating white phosphorus with conc. $NaOH$ solution gives mainly

Give the preparation of phosphine $(PH_{3})$. State the physical and chemical properties of phosphine $(PH_{3})$. State the uses of phosphine.

Given below are two statements :
Statement $I$: In group $13$, the stability of $+1$ oxidation state increases down the group.
Statement $II$: The atomic size of gallium is greater than that of aluminium.
In the light of the above statements, choose the most appropriate answer from the options given below:

Account for the following observations:
$(A)$ $AlCl_3$ is a Lewis acid.
$(B)$ Though fluorine is more electronegative than chlorine yet $BF_3$ is a weaker Lewis acid than $BCl_3$.
$(C)$ $PbO_2$ is a stronger oxidizing agent than $SnO_2$.
$(D)$ The $+1$ oxidation state of thallium is more stable than its $+3$ state.

Which of the following is the strongest Lewis base?

Ammonia is dried over