On 5/22/2022 8:43 PM,
henh...@gmail.com wrote:
> pls wait 10 years before posting an Answer !
>
> ____________________________
>
> Two glasses of water with an ice-cube in each.
>
> All the conditions are the same in the two
> (volume, mass, temperature ...)
>
> --- except ... one of the glasses has very salty water.
Just a nit-picky follow-up: One molecule of water weighs (about) 18u,
while one of salt weighs about 58.5u. So, if the solutions in the two
glasses have equal mass, it means that for every 4 skillionths of a mole
of NaCl added you must remove 13 skillionths of a mole of water. It
would seem an astonishing coincidence if the solutions' volumes were
to come out equal, at equal temperature.
Or to put it another way: Salt water is denser than pure water of the
same temperature, so if the volumes are equal the masses cannot be,
and vice versa.
(I have long forgotten nearly all the chemistry I once knew, but even
when I still knew it my knowledge wasn't enough to let me calculuate the
abundances of H2O, H+, HO-, NaCl, Na+, and Cl- in either solution, never
mind the more exotic combinations that might crop up fleetingly. And
even if I knew their amounts, I still wouldn't have known how to figure
the density. But "salt water is denser" has remained with me, even if a
facility with equilibrium reactions has not.)
--
eso...@comcast-dot-net.invalid
Look on my code, ye Hackers, and guffaw!