Total number of moles for the reaction $2HI \rightleftharpoons H_2 + I_2$ at equilibrium,if $\alpha$ is the degree of dissociation,is:

For the reaction $A \rightleftharpoons nB$,if $a$ moles of $A$ are taken initially and $x$ moles of $A$ dissociate at equilibrium,find the value of the degree of dissociation.

The vapour density of $PCl_5$ at $25^{\circ}C$ is $100$. Calculate the degree of dissociation at this temperature.

Ammonia is heated in a closed vessel in the presence of a catalyst at $15 \ atm$ pressure and a temperature range of $27 \ ^\circ C$ to $347 \ ^\circ C$. Under these conditions,ammonia undergoes partial dissociation according to the reaction $2NH_3 \rightleftharpoons N_2 + 3H_2$. When the pressure is increased to $50 \ atm$ while keeping the volume of the vessel constant,calculate the percentage of $NH_3$ dissociated.

Ammonium carbamate $(NH_2COONH_4)$ when heated to $200\,^{\circ}C$ gives a mixture of $NH_3$ and $CO_2$ with a vapour density of $13.0$ at equilibrium. What is the degree of dissociation of ammonium carbamate?

$4 \ mol$ of $PCl_5$ is heated in a closed vessel at a constant temperature. If the degree of dissociation for $PCl_5$ is $0.5$,what will be the total number of moles at equilibrium?