The radius of the $Na^{+}$ ion is $95 \ pm$ and that of $Cl^{-}$ ion is $181 \ pm$. Predict the coordination number of $Na^{+}$ in $NaCl$.

Choose the incorrect statement from the following:

$A$ box of $1 \, L$ capacity is divided into two equal parts by a thin partition,which are filled with $2 \, g$ of $H_2$ and $16 \, g$ of $CH_4$ respectively. The temperature of each part is $T$. The pressure in each part is $P$. If the partition is removed,the total pressure will be:

If the rate of diffusion of a gas having twice the molecular mass of nitrogen is $56 \ mL \ s^{-1}$,then the rate of diffusion of nitrogen will be ........... $mL \ s^{-1}$.

Equal masses of three non-reacting different ideal gases $X, Y$ and $Z$ are mixed in a sealed rigid container. If the temperature of the system remains constant at $400 \ K$,which of the following statements about gas $X$ can never be correct?

Equal volumes of monoatomic and diatomic gases at same initial temperature and pressure are mixed. The ratio of specific heats of the mixture $({C_p}/{C_v})$ will be