Question

500.0 mL of a gas was collected at 20.0 C and 720.0 mmHg. What is it’s volume at STP

Answer 1

Answer:

The volume at STP is 0,441 L (441ml)

Explanation:

We use the gas formula, which results from the combination of the Boyle, Charles and Gay-Lussac laws. According to which at a constant mass, temperature, pressure and volume vary, keeping constant PV / T. The conditions STP are 1 atm of pressure and 273K of temperature. We convert the unit Celsius into Kelvin, the volume in ml into L and the pressure in mmHg into atm:

0 ° C = 273K, 20 ° C = 273 + 20 = 293K ; 500/1000= 0,500 L

760mmHg---1 atm

720mmHg----x= (720mmHgx 1 atm)/760mmHg= 0,947 atm

P1xV1/T1= P2xV2/T2

V2=((P1xV1/T1)xT2)/P2

V2=((0,947atmx0,500L/293K)x273K)/1 atm

V2= 0,441 L