Since you are measuring pressure in mmHg, which value of R should you use? Suppo
ID: 915586 • Letter: S
Question
Since you are measuring pressure in mmHg, which value of R should you use?
Suppose you have a stoppered flask containing CO2 gas at room temperature and pressure. If the volume of your stoppered flask is 300.0 mL, the pressure in the room is 770 mm Hg, and the temperature in your work area is 22.0°C, how many moles of CO2 are in the flask?
How many grams of CO2 are in the flask (described in part b)?
Why do we measure the volume of the flask with water rather than using the volume listed on the side?
Why is the flask not firmly stoppered during sublimation
Explanation / Answer
R = 0.082 Latm/molK since 1 atm = 760 mm Hg then
760*0.082 --> R = 62.32 Ltorr/molK
R = 62.32
Suppose you have a stoppered flask containing CO2 gas at room temperature and pressure. If the volume of your stoppered flask is 300.0 mL, the pressure in the room is 770 mm Hg, and the temperature in your work area is 22.0°C, how many moles of CO2 are in the flask?
PV = nRT
n = PV/(RT) = 770*0.3/(62.32*(22+273) = 0.01256500 mol of CO2
How many grams of CO2 are in the flask (described in part b)?
mass = mol*MW = 0.01256500 * 44 = 0.55286 g of CO2
Why do we measure the volume of the flask with water rather than using the volume listed on the side?
it is easier to measure
Why is the flask not firmly stoppered during sublimation
So Pressure remains constant