When nitrogen dioxide $(NO_2)$ is dissolved in water,what is the product formed?

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?

$A$ metal $(X)$ dissolves in both dilute $HCl$ and dilute $NaOH$ to liberate $H_2$ gas. Addition of $NH_4Cl$ and excess $NH_4OH$ to an $HCl$ solution of $(X)$ produces $(Y)$ as a precipitate. $(Y)$ is also produced by adding $NH_4Cl$ to the $NaOH$ solution of $(X)$. The species $(X)$ and $(Y)$,respectively,are:

The oxidation state of phosphorus in cyclo-tri-meta phosphoric acid is

Among the hydrides $NH_3, PH_3,$ and $BiH_3$,the hydride with the highest boiling point is $X$ and the hydride with the lowest boiling point is $Y$. What are $X$ and $Y$ respectively?

Bones glow in the dark because