Question

50 POINTS! I really need help with these pressure and volume questions from Boyle's Law. PLEASE HELP

1.If a sample of gas has a volume of 100.0ml when the pressure is 50.0kPa, what is the volume when the pressure is increased to 400.0kPa, assuming temperature and number of moles is held constant?






2. What pressure would be required to take 100.0ml of a gas at 103.0kPa and squish it down to 2.00ml, assuming temperature and number of moles is held constant?






4. If the temperature and number of moles are held constant, what would be the new volume if 2.00cm3 of a gas at 3.00atm is changed to 0.0200atm?






7. What pressure must be applied to a sample of Freon gas having a volume of 325L at 20.0°C and 723Torr to permit the expansion of the gas to a volume of 975L at 20.0°C?

Answer 1

1)
`V_(1)`= 100ml = 0.1 L

2)
`P_(1)`= 50kPa

`1) P_(2) =400 kPa\\2)V_(2) =?`

So,

`P_(1)V_(1) = P_(2) V_(2)`

`V_(2) = (0.1 x 50)/(400)`

`V_(2) = 0.0125 L`

`2) V_(1) = 100 mL = 0.1 L\\P_(1)= 103 kPa\\V_(2)=2 mL\\P_(2) =?\\`

`P_(1) V_(1) =P_(2) V_(2)\\ P_(2)=(0.1x103)/(2)\\ P_(2)=5.15 kPa`

`4) V_(1)=2 cm^(3) = 0.002 dm^3\\P_(1) =3 atm x 760 = 2280 torr\\P_(2) = 0.0200 atm x 760=15.2 torr`

Same, formula as above,

`V_(2)=(2280x0.002)/(15.2)\\V_(2)=0.3 L`

`7)V_(1)=325\\T_(1)=20^(0)C=293K\\ P_(1)=723 torr\\V_(2)=975L\\T_(2) = 20^0 C= 293K\\P_(2)=?`

By the formula,

`(P_(1)V_(1))/(T_(1)) = (P_(2)V_(2))/(T_(2)) \\P_(2) = (723x325x293)/(293x975)`

`P_(2) =241 Torr`