An organ pipe is blown with carbon dioxide and produces waves 2 ft long and a note with a frequency if 350 Hz. What is the velocity of sound in carbon dioxide? How do you account for the fact that this is not the same as the velocity in air?

Use the formula (but be careful with the units!):

v = f\lambda

where v is the velocity of the sound wave
f the frequency of the wave
lambda is the wavelength.

Now, you can do the comparison with the speed of sound which is 330 m/s in air.