Verified answer

Use the formula P1V1/T1 = P2V2/T2

Solve for V2:

V2 = P1V1T2/T1P2

Convert to proper units:

35C = 273 + 35K = 308K

772 mmHg = 1.016 atm

Plug in the numbers:

V2 = 1.016atm x 3.5L x 273K/308K x 1.00atm = 3.15L

The method described by the 2 others does work; but it is mathmatical equivalent of going to your next door neighbor's house by going all the way around the block and coming from the other side.

Norrie: you were right; the math was set up right, but the number was a little off, don't know how that slipped by my QC! It's fixed now.

Kelvin Temperature is required for these calculations = °C + 273.

STP = 273K (0°C + 273) and 1 atmosphere pressure (760mmHg). (We don't have to convert to atm).

Using the Combined Gas Law. P1V1T2 = P2V2T1

P1 (772mmHg) x V1 (3.5 L) x T2 (273K).

P2 (760mmHg) x V2 (?) x T1 (308K).

V2 = (772 x 3.5 x 273) / (760 x 308)

= 737,646 / 234,080 = 3.15 L. Final volume.

Use the given pressure, temperature and volume to calculate n in the equation PV=nRT (n=PV/RT). Then plug in that n value to a new equation with the values for standard pressure and temperature. If you solve for volume, you'll get V=nRT/P.

You need to convert is to joules and kelvin then use the ideal gas law.

PV = nRT

Pressurex volume = number of moles x universal gas constant (8.3145 joules/mol K) x temperature in kelvin.