To find the volume of the dry CO2 at STP, we first need to find the volume of the CO2 collected over water and then correct for the water vapor pressure.
Step 1: Convert the temperature to Kelvin
STP is at 0 ºC, which is 273 K. The given temperature is 19 ºC, which is 19 + 273 = 292 K.
Step 2: Correct for water vapor pressure
The total pressure in the collection container is the barometric pressure minus the vapor pressure of water:
Total pressure = 742 mmHg - 17 mmHg = 725 mmHg
Step 3: Convert the volume of CO2 collected over water to STP
Use the combined gas law:
(P1V1)/T1 = (P2V2)/T2
Where:
P1 = 725 mmHg
V1 = 407 mL
T1 = 292 K
P2 = 760 mmHg (STP)
V2 = volume of dry CO2 at STP
T2 = 273 K
(725 mmHg * 407 mL)/292 K = (760 mmHg * V2)/273 K
V2 = (725 mmHg * 407 mL * 273 K)/(292 K * 760 mmHg)
V2 = 211.5 mL
Step 4: Convert the volume to liters
1 L = 1000 mL
V2 = 211.5 mL * (1 L / 1000 mL) = 0.2115 L
Therefore, the volume of the dry CO2 at STP is 0.2115 liters.
In this reaction, 407 mL of CO2 are collected over water. The temperature in the room is 19 ºC and the barometric pressure is 742
mmHg. What will the volume (in liters) of the dry CO2 be at STP? (at 19 ºC the vapor pressure is 17 mmHg).
1 answer