Question

At constant volume and temperature conditions, the rate of diffusion $D_{A}$ and $D_{B}$ of gases $A$ and $B$ having densities $\rho_{A}$ and $\rho_{B}$ are related by the expression

• A. $D_{A}= \left[D_{B}. \frac{\rho_{A}}{\rho_{B}}\right]^{1/ 2}$
• B. $D_{A}= \left[D_{B}. \frac{\rho_{B}}{\rho_{A}}\right]^{1 /2}$
• C. $D_{A}=D_{B} \left(\frac{\rho_{A}}{\rho_{B}}\right)^{1/ 2}$
• D. $D_{A}=D_{B} \left(\frac{\rho_{B}}{\rho_{A}}\right)^{1 /2}$

Answer 1

Answer: (D)

$\frac{D_{A}}{D_{B}}=\sqrt{\frac{\rho_{B}}{\rho_{A}}}=\left[\frac{\rho_{B}}{\rho_{A}}\right]^{\frac{1}{2}} $
$\therefore D_{A}=D_{B} \left(\frac{\rho_{B}}{\rho_{A}}\right)^{\frac{1}{2}}$