$BiCl_3$ on hydrolysis forms a white precipitate of

Nitrogen dioxide $(NO_2)$ reacts with water to give:

Which of the following reactions correctly represent the products formed upon heating?
$(a) \ NH_4NO_2 \xrightarrow{\Delta } N_2 + 2H_2O$
$(b) \ NH_4NO_3 \xrightarrow{\Delta } N_2O + 2H_2O$
$(c) \ Na_2CO_3 \xrightarrow{\Delta } Na_2O + CO_2$
$(d) \ NH_4Cl \xrightarrow{\Delta } NH_3 + HCl$

$NO_2$ is a mixed oxide. This is proved by the fact that it reacts with $H_2O$ and then with $NaOH$ to form:

In the Haber process,hydrogen is obtained by reacting methane with steam in the presence of a $NiO$ catalyst. This process is known as steam reforming. Why is it necessary to remove $CO$ when ammonia is obtained by the Haber process?

$Pb + \text{dil. } HNO_3 \xrightarrow{\text{Warm}} P + Q \uparrow + H_2O$
The incorrect statement for $Q$ is: