The Ideal Gas Law Syringe demonstration uses a syringe to illustrate the relationship between pressure, volume, and temperature in an ideal gas. By varying the volume of the gas inside the syringe and measuring the resulting changes in pressure, students can observe how the gas behaves according to the ideal gas law, PV=nRT. When the gas is compressed or expanded by moving the syringe plunger, the pressure changes inversely with volume, demonstrating Boyle's Law. Additionally, heating or cooling the gas inside the syringe while keeping the volume constant shows the direct relationship between temperature and pressure, illustrating Gay-Lussac's Law.