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

At $STP$,the density of air is $0.001293 \ g \ mL^{-1}$. Its vapour density is $---$.

The equation $\alpha = \frac{D - d}{(n - 1)d}$ represents the degree of dissociation. For which of the following reactions is this equation valid,where $D$ is the theoretical vapour density and $d$ is the observed vapour density?

Ammonium carbonate,when heated to $200\, ^oC$,dissociates into a mixture of $NH_3$ and $CO_2$ vapors with a vapor density of $13.0$. What is the degree of dissociation of ammonium carbonate?

For the equilibrium reaction $N_2O_{4(g)} \rightleftharpoons 2NO_{2(g)}$,the value of $K_p$ is $2$. Calculate the percentage dissociation of $N_2O_{4(g)}$ at a total pressure of $0.5 \ atm$. (in $\%$)

The degree of dissociation of $PCl_5$ $(\alpha)$ obeying the equilibrium $PCl_5 \rightleftharpoons PCl_3 + Cl_2$ is related to the pressure at equilibrium $(P)$ by: