Question

Hydrogen has two naturally occurring isotopes, 1H and 2H. Chlorine also has two naturally occurring isotopes, 35Cl and 37Cl. Thus, hydrogen chloride gas consists of four distinct types of molecules: 1H35Cl, 1H37Cl, 2H35Cl, and 2H37Cl. Place these four molecules in order of decreasing rate of effusion.

Answer 1

Answer:

Molecules in order of decreasing rate of effusion:

$^1{H}^{35}Cl>^2H^{35}Cl>^1H^{37}Cl>^2H^{37}Cl$

Explanation:

Mass of $^1H^{35}Cl$ gas= $M_1= 36 g/mol$

Mass of $^1H^{37}Cl$ gas =$M_2= 38 g/mol$

Mass of $^2H^{35}Cl$ gas =$M_3= 37 g/mol$

Mass of $^2H^{37}Cl$ gas =$M_4= 39 g/mol$

According Graham's law:

'The rate of effusion or diffusion of gas is inversely proportional to the square root of the molar mass of the gas'.The equation given by this law follows the equation:

$\text{Rate of diffusion}\propto \frac{1}{\sqrt{\text{Molar mass of the gas}}}$

So, higher the molecular mass of the gas lower will be the effusion rate and vice versa.

Increasing order of molecular masses of the given gases:

$M_1$

Decreasing order of effusion rate respective to gases:

$R_1>R_3>R_2>R_4$

Molecules in order of decreasing rate of effusion:

$^{1}\textrm{H}^{35}Cl> ^{2}\textrm{H}^{35}Cl>^{1}\textrm {H}^{37}Cl>^{2}\textrm{H}^{37}Cl$