chem
posted by hhh .
A typical party balloon when inflated has a volume of 7.3 L. How many moles of helium are in the balloon if the pressure of helium is 1.2 atm and the temperature is 20.7 °C? Take the value of R to be 0.08206 Latm/molK.

Use PV = nRT
Remember T must be in kelvin.