Hydrolysis of phosphorus trichloride in water gives:

Match the following:

Compound	Nature
$i$. $PbO_2$	$a$. Acidic
$ii$. $Sb_2O_3$	$b$. Basic
$iii$. $GeO_2$	$c$. Amphoteric

For $H_3PO_3$ and $H_3PO_4$,the correct choice is:

Which one of the following combines with $Fe(II)$ ions to form a brown complex?

When $NH_3$ is passed over heated $CuO$,what is it oxidized to?

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