Ideal Gas Law?

[bigdudettedog]

Which of the following statements are true according to the ideal gas law for a gas cylinder of fixed volume filled with one mole of oxygen?

a. when the pressure changes from 15C to 30C, the pressure inside the cylinder doubles.

b. when a second mole of oxygen is added to the cylinder, the ratio temperature/pressure remains constant.

c. an identical cylinder filled with the same pressure of hydrogen contains more molecules because hydrogen molecules are smaller than oxygen molecules.

d. when a second mole of oxygen is added to the cylinder, the ration temperature/pressure decreases by 50%

my guess is
a. false
b. false
c. true
d. false

what do you guys think? thank you!
i knew for sure a. is false since the temperature is not in kelvins. celsius gets you every time in these gas law things...

[Trevor D]

I'm pretty sure that A is false. Isn't the temperature in Kelvin?

[gladys]

Sorry, but you haven't got this right.

a
Gay Lussac's Law - pressure is directly proportional to temperature. If you double temp, you double pressure. True

b
You have got this one right. Doubling the number of moles doubles the ratio P:T according to PV=nRT. Thus it will halve the ratio T:P.

c
False
I mole of any gas occupies the same volume at constant temperature and pressure (except for extreme situations). This is because the size of the gas molecules is insignificant compared to the space between them.

d
This is much the same as b. Answer is true.

[gladys]

Sorry, but you haven't got this right.

a
Gay Lussac's Law - pressure is directly proportional to temperature. If you double temp, you double pressure. True

b
You have got this one right. Doubling the number of moles doubles the ratio P:T according to PV=nRT. Thus it will halve the ratio T:P.

c
False
I mole of any gas occupies the same volume at constant temperature and pressure (except for extreme situations). This is because the size of the gas molecules is insignificant compared to the space between them.

d
This is much the same as b. Answer is true.