The velocity of sound in air at 25 degrees Celsius is approximately 346 meters per second (m/s).

Here's how to calculate it:

* Formula: The speed of sound in air is calculated using the following formula:

v = 331.5 + 0.606 * T

where:

* v = velocity of sound (m/s)

* T = temperature in degrees Celsius

* Calculation:

v = 331.5 + 0.606 * 25

v = 331.5 + 15.15

v = 346.65 m/s

Therefore, the approximate velocity of sound in 25 Celsius air is 346 m/s.