Astudent collects 350 ml of a vapor at a temperature of 67°c. the atmospheric pressure at the time of collection is 0.900 atm. how many moles of the gas does the student collect?

0.011 moles.
0.053 moles
0.11 moles
0.53 moles

First option 0.011 moles

Explanation:

You need to use the formula for Ideal gases which is:

PV = nRT

Where:

P = Pressure (in atm)

V = Volume (In Liters)

n = moles

R = gas constant (this depends of the units; in this case is 0.082 L atm/K)

T = temperature (In K)

From the formula above, we can solve for n:

n = PV / RT

Let's convert first the temperature and volume to K and L respectively:

T = 67 + 273 = 340 K

V = 350 mL / 1000 = 0.35 L

Finally, let's put all the values in the formula above to solve for the value of n:

n = 0.9 * 0.35 / 0.082 * 340

n = 0.315 / 27.88

n = 0.011 moles

c. heat could easily travel through the molecules in the air and escape/enter the flask. removing the air slows down the heat transfer.