Scott, I believe both you and Harry mean "mass", not "weight" and not "Weight/mass" of a gas.
There is a difference in SI, as most of us in this USMA forum well know! Consider specified volumes of gases (at known T and p) condensed into liquid forms of definite respective masses. They are then easy to visualize, even if the liquid forms are transparent, by reflections off their surfaces. Gene. ---- Original message ---- >Date: Tue, 19 Jun 2007 22:20:35 -0700 >From: James Scott Hudnall <[EMAIL PROTECTED]> >Subject: [USMA:38938] Re: Weight/mass of a gas >To: "U.S. Metric Association" <[email protected]> > > It is listed by weight so that it can be expressed > as a single number. > If you express it as a volume, you have to also give > temperature and atmospheric pressure to be precise > about the quantity of gas. > On 2007-06 -19, at 20:42 , Harry Wyeth wrote: > > > > We read a lot about xxx tons of CO2 or whatever, > but I have trouble imaging the weight of a volume > of a gas. I have read that water is about 800 > times denser than air, so from that one could > calculate the weight of a cubic meter of air, for > example. But how about other gases? Is there a > metric rule of thumb? Why do engineers measure > the output of a gas by weight in the first place? > > HARRY WYETH
