Chapter 13, Problem 48PE

There are two important isotopes of uranium− ${}^{\text{235}}\text{U}$ and ${}^{\text{238}}\text{U}$ ; these isotopes are nearly identical chemically but have different atomic masses. Only ${}^{\text{235}}\text{U}$ is very useful in nuclear reactors. One of the techniques for separating them (gas diffusion) is based on the different average velocities v_rms of uranium hexafluoride gas. ${\text{UF}}_{\text{6}}$. (a) The molecular masses for ${}^{\text{235}}{\text{U UF}}_{\text{6}}$ and ${}^{\text{238}}{\text{U UF}}_{\text{6}}$ are $\text{349}.0\text{ g}/\text{mol}$ and $\text{352}.0\text{ g}/\text{mol}$, respectively. What is the ratio of their average velocities? (b) At what temperature would their average velocities differ by $\text{1}.00\text{ m}/\text{s}$ ? (c) Do your answers in this problem imply that this technique may be difficult?