Which of the following compounds does not produce ammonia upon heating?

Which of the following oxides of nitrogen is isoelectronic with $CO_2$?

Match the following List-$I$ (Acid) with List-$II$ (Reagents used for preparation):
| List-$I$ (Acid) | List-$II$ (Reagents used for preparation) |
| :--- | :--- |
| $A. H_3PO_2$ | $I. \text{Red } P_4 \text{alkali}$ |
| $B. H_4P_2O_5$ | $II. \text{White } P_4 \text{alkali}$ |
| $C. H_3PO_4$ | $III. PCl_3; H_3PO_3$ |
| $D. H_4P_2O_7$ | $IV. P_2O_5; H_2O$ |
| | $V. H_3PO_4; \Delta$ |

The correct order of reducing abilities of hydrides of group $15$ elements is:

Which of the following reactions is a part of the large-scale industrial preparation of nitric acid?

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