[MrBigglesworth]

When you use the term "part" in a formula, does it mean it in the sense of it being a ratio? I.E.:
"1 gram of sodium to 5 grams of chlorine"
is equal to
"1 part sodium to 5 parts chlorine"
is equal to
"3 grams of sodium to 15 grams of chlorine"

Is that how the term "part" is correctly used?
Or is it a unit of measurement (6 milligrams, 9 grams, etc)?
Please *delete me* My chemistry teacher is sick for the week (the flu    ), and so I can't ask him. Please *delete me* (He likes these wierd forms of chemical vernacular...  )

[Mitch]

You have half the concept right. When we say 1 part X to 5 parts Y, we NEVER MEAN GRAMS! It is only useful as moles. Where it should of been 1 mole of X to 5 moles of Y.

[MrBigglesworth]

mole? so you DO mean in terms of a ratio, right? '1 part to 5 parts' means that the one part (say, 3 grams) would be multiplied by 5 ('1 part to 5 parts' ) to get the amount of the other chemical to add, right? the latter must be a multiple in terms of the other chemical, right? (1 part = 3 grams  >so<   5 parts = 3 * 5 = 15  >so<  ==>  5 parts = 15 grams)
Is this right?

[Mitch]

It is never used for GRAMS!!!!!!!!!!!!!!!!!!!!!!!

[MrBigglesworth]

Grrr! I know! I am just using an analogy to try to verify what you said; when someone uses parts in a chemical formula, the amount of chemicals used can determine the size of the batch, right? I know when they use 'part', they mean the amount of chemical(s) that you use can vary, as long as they are proportioned equally by the ratio of the number of 'parts' that you put in of each. Is that correct?

[jdurg]

In chemistry, 'parts' is another term for mole.  So saying 1 part sodium and 1 part chlorine means one MOLE of sodium and one MOLE of chlorine.  Grams has nothing to do with the ratio.  (Since in terms of grams, it would be 23 'parts' sodium and 35 'parts' chlorine.  See why parts aren't used to describe grams?  It just leads to unneccesary confusion and numbers that are just too high).  You can basically think of the term 'parts' as another name for the coefficient in a chemical equation.  In the equation 2Al(s) + 3Br₂(l) -> 2AlBr₃(s), you could say that as 2 parts aluminum plus 3 parts bromine gives you 2 aluminum bromides.  Now if someone didn't know chemistry, they might think two parts in terms of volume or mass and wind up completely off in terms of the reaction.  That is why you NEVER use vague measurements such as 'parts' or 'equivilants' in chemistry.  Always define the units that you are using.  ALWAYS.  

[MrBigglesworth]

so how does that translate into amounts of matter? I kinda see what you mean, but...I dont get it...
I'm still confused..