Chapter 5.7, Problem 1RCF

Interpretation Introduction

Interpretation:

Among the given quantities which one is one mole each of Helium and Chlorine gas equal to each other have to be identified.

Concept Introduction:

Root mean-square speed is the parameter to measure the speed of particles in a gas.  M is the molecular mass of the molecule at temperature T, root mean-square speed (${\text{u}}_{\text{rms}}$) has to be calculate using the formula

  ${\text{u}}_{\text{rms}}\text{=}\sqrt{\frac{\text{3RT}}{\text{M}}}$

Graham's law of effusion told as the rates of effusion of two different gases vary inversely as the square roots of the mass of their particles.

The rate of effusion is the number of molecules passing through a porous barrier in a given time.  The longer it takes, the slower the rate of effusion.

Using given equation we find the molar mass of unknown gas

  $\frac{{\text{r}}_{\text{1}}}{{\text{r}}_{\text{2}}}\text{=}\frac{{\text{t}}_{\text{1}}}{{\text{t}}_{\text{2}}}\sqrt{\frac{{\text{M}}_{\text{2}}}{{\text{M}}_{\text{1}}}}$