n = number of mole of sample of helium gas = 4.10
T = temperature of the gas = 28 °C = 28 + 273 = 301 K
V = Volume of helium gas = 3.28 L = 0.00328 m³
P = pressure of the helium gas
Using the equation
P V = n R T
P (0.00328) = (4.10) (8.314) (301)
P = 3.13 x 10⁶ Pa
P = (3.13 x 10⁶ Pa) (1 atm/(101325 Pa))
P = (3.13 x 10⁶ ) atm/(101325)
P = 30.89 atm