Question

At 300 kelvin the density of a certain gaseous molecule at a at 2 bar is double to that of dr dinitrogen and 284 was the molar mass of gaseous molecule is

Answer 1

seems your question is incorrect. A correct question should be ----> At 300 K, the density of a certain gaseous molecule at 2 bar is double to that of dinitrogen at 4 bar. The molar mass of gaseous molecule is :



solution : we know, d = PM/RT
where d is density of gas,
P is pressure, M is molar mass of gas
and T is temperature of gas.

so, at constant temperature ,
$\frac{d_1}{d_2}=\frac{P_1M_1}{M_2M_2}$

assume, $d_1,P_1,M_1$ are density, pressure and molar mass of certain gas respectively. and $d_2,P_2,M_2$ are density , pressure and molar mass of dinitrogen respectively.

given, $d_1=2d_2$, $P_1=2bar$
$P_2=4bar$ and $M_2=28g/mol$

so, $\frac{2d_2}{d_2}=\frac{2M_1}{4\times28}$
M = 28 × 4 = 112g/mol