Question

The ratio of de-Broglie wavelength of molecules of hydrogen and helium in two gas jars kept separately at temperatures of 27ºC and 127ºC respectively is –

• A. 2/$\sqrt{3}$
• B. 2/3
• C. $\sqrt{3}$/4
• D. $\sqrt{8/3}$

Answer 1

Answer: (D)

$\sqrt{8/3}$

Answer 2

$\frac{\lambda_{H_{2}}}{\lambda He}$ = $\frac{\frac{25.6}{\sqrt{2}\sqrt{300}}}{\frac{25.6}{\sqrt{4}\sqrt{400}}}$ = $\sqrt{\frac{16}{6}}$= $\sqrt{\frac{8}{3}}$