A one metre long (both ends open) organ pipe is kept in a gas that...

$V = \sqrt{\dfrac{B}{ρ}}$
$\dfrac{{V}_{pipe}}{{V}_{air}} = \dfrac{\sqrt{\dfrac{B}{2ρ}}}{\sqrt{\dfrac{B}{ρ}}} = \dfrac{1}{\sqrt{2}}$
${V}_{pipe} = \dfrac{{V}_{air}}{\sqrt{2}}$
${f}_{n} = \dfrac{( n + 1 ) {V}_{pipe}}{2l}$
${f}_{1} - {f}_{0} = \dfrac{{V}_{pipe}}{2l} = \dfrac{300}{2\sqrt{2}} = 105.75Hz\left(if\sqrt{2} = 1.41\right)$
$= 106.05Hz\left(if\sqrt{2} = 1.414\right)$