In the reaction $4HNO_3 + P_4O_{10} \to 4HPO_3 + x$,the product $x$ is

Phosphorus reacts with chlorine gas to give a colourless liquid,which fumes in moist air to produce $HCl$ and

$Sn$ is dissolved in excess of $NaOH$ solution,the compound obtained is

The maximum number of $P-H$ bonds is present in a molecule of:

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

$A$ gas at low temperature does not react with most compounds. It is almost inert and is used to create an inert atmosphere in bulbs. The combustion of this gas is exceptionally an endothermic reaction. Based on the given information,we can conclude that the gas is