Sciencemadness Discussion Board

gas calculations

soma - 9-9-2014 at 13:48

I'm new to figuring out gas calculations and wanted to check to make sure I did it right.

LiAlH4 + 4 H2O ===> LiOH + Al(OH)3 + 4 H2

100 mgs. LiAlH4 = .00263 moles
.00263 x 4 = .0105 moles H2
.0105 moles H2 @ 22.4 litres / mol = .235 L (235 ml)
(293K / 273K ) x 235ml = 252 ml @ 20C
20 mgs. LAH ~ 50 ml H2 @ 20C

Magpie - 9-9-2014 at 14:01

perfect!

soma - 9-9-2014 at 14:03

Thanks.

aga - 9-9-2014 at 14:52

I thought STP meant 25 C ?

careysub - 9-9-2014 at 15:27

Quote: Originally posted by aga  
I thought STP meant 25 C ?


For IUPAC STP is 0C, for NIST it is 20C.

Two standards, ain't that always the way?