Among the following oxides of $p$-block elements,the number of oxides having amphoteric nature is: $Cl_2O_7, CO, PbO_2, N_2O, NO, Al_2O_3, SiO_2, N_2O_5, SnO_2$

Assertion : Stannous chloride gives grey precipitate with mercuric chloride,but stannic chloride does not do so.
Reason : Stannous chloride is a powerful oxidising agent which oxidises mercuric chloride to metallic mercury.

How is dry ice produced? Mention its uses.

Which of the following statements are correct?
$i$. The basic structural unit of silicates is $SiO_4^{4-}$
$ii$. Silicones are biocompatible
$iii$. Producer gas contains $CO$ and $N_2$
The correct option is

Which one of the following is correct about the stability of the given ions?

Explain the following reactions:
$(a)$ Silicon is heated with methyl chloride at high temperature in the presence of copper;
$(b)$ Silicon dioxide is treated with hydrogen fluoride;
$(c)$ $CO$ is heated with $ZnO$;
$(d)$ Hydrated alumina is treated with aqueous $NaOH$ solution.