Heating $(NH_4)_2Cr_2O_7$ produces a gas. This gas can also be obtained by:

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

Identify the $INCORRECT$ statement$(s)$ among the following:
$(I)$ Moist ammonia gas can be dried by using anhydrous $CaCl_2$
$(II)$ Phosphine is a weaker base than ammonia
$(III)$ $R_3SiCl$ produces very complex cross-linked polymeric silicone on hydrolysis
$(IV)$ When metallic copper reacts with $6 \ M$ $HNO_3$,$NO_2$ is the only product

Phosphorus pentachloride in the solid state exists as:

Elements $X$ and $Y$ belong to Group $15$. The difference between the electronegativity values of $X$ and phosphorus is higher than that of the difference between phosphorus and $Y$. $X$ and $Y$ are respectively:

Which of the following is metaphosphoric acid?