Question

how does speed of sound change with temperature of medium?

Answer 1

Dependence of the speed of sound on the properties of the medium:

The speed of sound is variable and depends mainly on the temperature and the properties of the substance through of which the wave is traveling. For example, in low molecular weight gases, such as helium, sound propagates faster compared to heavier gases, such as xenon. In a given ideal gas the sound speed depends only on its temperature. At a constant temperature, the ideal gas pressure has no effect on the speed of sound, because pressure and density (also proportional to pressure) have equal but opposite effects on the speed of sound, and the two contributions cancel out exactly. In non-ideal gases, such as a van der Waals gas, the proportionality is not exact, and there is a slight dependence on the gas pressure, even at a constant temperature. Humidity also has a small, but measurable effect on sound speed (increase of about 0.1% to 0.6%), because some oxygen and nitrogen molecules of the air are replaced by the lighter molecules of water.