Jason: Evidently you didn't read all the way to the end, where Remek refers to PSI (pounds per square inch, remember). So he's not confusing either weight or mass with pressure.
Bill ________________________________ Bill Potts Roseville, CA http://metric1.org [SI Navigator] -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jason Darfus Sent: Monday, June 30, 2008 18:25 To: U.S. Metric Association Subject: [USMA:41290] Re: Hydrogen fuel for autos sold by the kilogram You're confusing weight and pressure. I quite often hear people refer to pressure by only saying 'pounds' (I put 35 pounds of air in my car tire). If that were the case, an inflated car tire would weight significantly more than a flat tire. It's been a while since I took chemistry, so please correct me if I'm wrong: it seems that selling H2 by the kilogram is due to the connection to molecular weight, which is grams per mol. By using kilograms, you can determine fairly accurately how many atoms of hydrogen you're buying. On 30 Jun 2008, at 21:07, Remek Kocz wrote: > Hmmm, isn't chemical engineering stuck mainly in imperial mode in the > US? I always thought that liquid/solid gases would have been sold by > the pound, since their pressures in tanks are measured in PSI. > > Remek >
