Answer:
The new pressure exerted by the He, is 1266.6 Torr
Step-by-step explanation:
A typical problem of gases where the volume is increased and the moles and T° keeps on constant. This is an indirect proportion because when the volume of the flask is increased, pressue decreases because molecules collide to a lesser extent with the walls of the vessel.
P₁ . V₁ = P₂ . V₂
760 Torr . 5L = P₂ . 3L
P₂ = (760 Torr . 5L) / 3L
P₂ = 1266.6 Torr