A man used a hydrogen-filled balloon to fly from Paris 25km into the French side. What’s the mass density of hydrogen relative to air at the same temperature/pressure? What mass of payload can be lifted by 10kg of hydrogen, neglect the mass of the balloon?

 

 

What work have you done on the problem?

Also you'll need extra data (find it online) to compare to air density.

 

What will be the volume of your hydrogen at, say, standard temperature and pressure?

Standard Stage:

 

Vol= 24.8 dm^3

Pressure: 1 atm

 

I'm not sure where to start or formula to use, not sure if the formula PV=nRT?

Standard Stage:

 

Vol= 24.8 dm^3

Pressure: 1 atm

 

I'm not sure where to start or formula to use, not sure if the formula PV=nRT?

 

PV=nRT is a good place to start

I'm not sure where to start or formula to use, not sure if the formula PV=nRT?

 

Yes, that is a very useful formula. n you can calculate for a given mass of sample, R is a constant. So long as you're dealing with ideal gases (which should be the case here), then the effects of P and T will be the same for both gas samples, so that they will cancel out.

If P and T cancels out, so R is given and V is 24.8 dm^3, I calculate for n

 

 

PV= nRT

V= nR

n= V/R

n= 24.8/.0826 = 302.21mol * 4g/mol = 1208g

 

 

 

4g/mol?

oh crap i take He g/mol instead of H2, so the answer is 302.21g