Step 1: Recall absolute zero.
Absolute zero is the lowest theoretical temperature at which the volume of an ideal gas becomes zero.
Step 2: Relate Celsius and Kelvin scales.
Absolute zero corresponds to \(0\,\mathrm{K}\), which is equal to \(-273.15^\circ\mathrm{C}\).
Step 3: Conclusion.
Therefore, the volume of a gas becomes absolutely zero at \(-273.15^\circ\mathrm{C}\).