$($b$)$ A U$-$tube manometer contains a fluid with a density of $825k\frac{g}{m^3}.$ The difference in height of the two columns are $35cm.$ What is the pressure difference $(kPa)?$ What would the pressure difference be $($atm$)$ if instead of the above fluid, the manometer contained mercury $($density $13600k\frac{g}{m^3})$ and the difference in height was still $35cm?[$ Assume $1$atm$=101\mathrm{.}325$kPa,$g=[$:$9\mathrm{.}8\frac{m}{s^2}\}$

Question Number IV $($Mole$,$ mole fraction, mass fraction$)$

$($a$)$ How many moles of $N$ atoms are present in $34kg$ of ammonia $(N{H}_3)?$ Additionally, how many nitrogen atoms are there? $($Given molar mass of: $N=14,H=1)$