#CHEMISTRY ADD IN WORD MOLECULES MANUAL#
#CHEMISTRY ADD IN WORD MOLECULES ARCHIVE#

#CHEMISTRY ADD IN WORD MOLECULES MANUAL#

Translated via ( with some manual changes. Anyway, this quantity is often written as Mol., so you only have to omit the point.' 'In order not to always have to use the sluggish expression gram-molecular weight, I will simply call this quantity Mol in the following, and allow me to recommend this proposal for general acceptance. Man schreibt ohnedies diese Größe häufig Mol., und braucht daher nur den Punkt fortzulassen.' 'Um nicht stets den schleppenden Ausdruck Gramm -Molekulargewicht brauchen zu müssen, werde ich diese Größe in der Folge kurzweg Mol nennen, und erlaube mir, diesen Vorschlag zur allgemeinen Annahme zu empfehlen.

This book is available on Google Books (pg 278). Ostwald Hand- und Hilfsbuch zur Ausführung physikochemischer Messungen.

#CHEMISTRY ADD IN WORD MOLECULES ARCHIVE#

I believe the Internet Archive has an English translation of his historically famous book of 19th century. the quantity of an element having a mass in gramsĪs per your exercise, if 1 amu were 1/24 the mass of carbon-12 (12 exact), then all atomic weights double.Ĭoming to the mole, The symbol mol is due to Ostwald who was a very influential and respected physical chemist more than a century ago. Finally, in the 1960s, carbon-12 was set exact 12. Then came oxygen which was set to 16 exactly. Historically H was numerically set exact 1, and every atomic weight was measured with respect to that. Atomic weights have more than two hundred years old history. As you may note now, most the 'weighing' at atomic scale is defined circularly. that unit with gram and called it gram-atomic weight? Or ppl just took any relative microscopic unit like amu (in real life) or UM (in our hypothetical question) and just replaced the relative atomic weight w.r.t. kg/gm) of **amu ** as in the second approach?

Was the definition of 'gram-atom' pre-required the proper definition (w.r.t. So, which approach is correct (historically) ? Then the answer would be 1 gram-atom of Hydrogen = 1 mole of Hydrogen = $1N_A$ X $2UMs$ (No of UMs in 1 Hydrogen atom) = 1 gram And thus there would be $ 2N_A$ atoms of Hydrogen in one gram-atom of Hydrogen (as per new scale).īut, if I just use the definition of 1 gram-atom as nothing but 1 mole ( $1 N_A$) of atoms i.e. Gram-atomic weight: the amount of an atomic substance whose weight, in grams, is numerically equal to the atomic weight of that substance.Īccording to this definition, as the new scale will show the atomic weight of Hydrogen as 2 UMs, its gram-atomic weight should be 2 grams. The above question can have two answers if I use two available definitions of 'gram-atom' from the web : Find the gram-atomic weight of Hydrogen (H) as per the new scale ? Q: A new atomic mass scale, called UM, was introduced as 1/24th part of the mass of a single C-12 atom. But recently, I encountered a question that can have two different answers depending on how 'gram-atom' was defined early in Chemistry.

The terms 'gram-atom / gram-molecule' are obsolete nowadays in chemistry and got replaced by the concept of 'mole/ Avogadro Number'.

Chemistry add in word molecules