A spherical glass container of unknown volume contains helium gas at 25C and 1.960 atm. When a portion of the helium is withdrawn and adjusted to 1.00 atm at 25C, it is found to have a volume of 1.75 cm^3. The fas remaining in the first container shows a pressure of 1.710 atm. Calculate the volume of the spherical container.

Question

Use PV = nRT to calculate n for the gas removed.
Then substitute this n in PV = nRT for the shperical container using P = 1.960 - 1.710 and solve for V.
Post your work if you get stuck.

1 atm X 1.75 cm^3 = n X(.08206)X 298.15K

n = 0.0715?
For the container.

(1.960 - 1.710 atm) X Volume = 0.0715 X (0.08206) X 298.15K.

Volume = 0.1429 cm^3?

That small?

Answer 1

the stepsare correct but the arthimetic is wrong somewhere in between. You should get 7 ml

Answer 2

agree with dmoney, the n value(moles) does not equal 0.0715, its 7.156 ^-3 which would make the answer 6.9938... or 7mL. Do not convert from mL to L in between, either do it at the beginning or the end.