How does concentrated $HNO_3$ react with aluminium?

Which of the following statements is correct for $N_2O_4$?

The orange solid on heating gives a colourless gas and a green solid which can be reduced to metal by aluminium powder. The orange and the green solids are,respectively

In the following reaction,identify the nature of the product formed by the complete hydrolysis of the underlined atom at $R.T.$:
$\underline{P}Cl_5 + H_2O \longrightarrow H_3PO_4 + HCl$

Phosphorus reacts with chlorine gas to give a colourless liquid,which fumes in moist air to produce $HCl$ and

Explain the molecular structure and properties of phosphorus trichloride $(PCl_{3})$.