[jubba]

Considering nitrogen gas and helium gas were ideal gases.
Connect a baloon to a cylinder of nitrogen and another balloon to a cylinder of helium and simultaneously start filling them up in a room. Which will fill first?
   I think helium will fill first. As the molecules in both gases will have the same kinetic energy but heliums mass is less. Thus it will have the higher velocity.

Is my answer and reasoning correct?

Thanks

[sdekivit]

Considering nitrogen gas and helium gas were ideal gases.
Connect a baloon to a cylinder of nitrogen and another balloon to a cylinder of helium and simultaneously start filling them up in a room. Which will fill first?
???I think helium will fill first. As the molecules in both gases will have the same kinetic energy but heliums mass is less. Thus it will have the higher velocity.

Is my answer and reasoning correct?

Thanks

mean squared velocity (MSV) = 3RT/M with M  = molecular weight.

thus MV = sqrt (3RT/M)

does you reasoning still holds ?

[gregpawin]

I think an interesting question to ask is if a balloon is made out of rubber, which is kind of like a spring in that it is harder to extend the more you extend it, why is it harder to first start blowing a balloon than when it is already half inflated?

[Mitch]

If the amount of moles delivered was the same then the volume of the ballons should also be the same, asumin Pressure and Temperature are constants.

[jubba]

I think an interesting question to ask is if a balloon is made out of rubber, which is kind of like a spring in that it is harder to extend the more you extend it, why is it harder to first start blowing a balloon than when it is already half inflated?

I'm not sure but is it because there is air already inside the balloon after you start blowing. So that although the force required to be applied to the balloon surface increases you now have some of the force being applied by the pressure of the gas already inside.