A sample of helium gas initially at 37.0°C,785 torr and 2.00 L was heated to 58.0°C while the volume expanded to 3.24 L.What is the final pressure in atm?

Question

Quizplus · Accepted Answer

Using the combined gas law:

(P₁V₁/T₁) = (P₂V₂/T₂)

where:

P₁ = initial pressure = 785 torr
V₁ = initial volume = 2.00 L
T₁ = initial temperature = 37.0°C + 273.15 = 310.15 K
P₂ = final pressure = ?
V₂ = final volume = 3.24 L
T₂ = final temperature = 58.0°C + 273.15 = 331.15 K

Solving for P₂:

(P₂) = (P₁V₁T₂)/(V₂T₁)
(P₂) = (785 torr)(2.00 L)(331.15 K)/(3.24 L)(310.15 K)
(P₂) = 509.5 torr

Converting torr to atm:

(P₂) = 509.5 torr / 760 torr/atm
(P₂) = 0.670 atm

Therefore, the final pressure in atm is 0.681 (rounded to three significant figures). The best choice is B.

A Sample of Helium Gas Initially at 37