What does parts mean

[Guest nrgnrg]

Does parts mean parts by weight?

 

A composition for example has the following:

 

5-15 parts A

5-15 parts B

45-75 parts C

 

What exactly does that mean?

 

Now let's say I have another composition where everything is given in pounds. How do I convert that to parts?

 

For example, let's say I have a total composition of 1000 lbs with the following:

 

500 lbs A

400 lbs B

100 lbs C

 

How do I convert these lbs to parts?

 

Any help would be appreciated

[mossoi]

I would assume this means parts of the whole and if the amounts given are in lbs then that's the way it's calculated.

 

500 lbs A - 5 parts

400 lbs B - 4 parts

100 lbs C - 1 part

 

It's just a ratio of the components.

[Guest nrgnrg]

How does the ratio definition explain the first example?

 

5-15 parts A

5-15 parts B

45-75 parts C

 

 

and what if we have 1907 lb composition where:

 

850 lbs for A

1050 lbs for B

7 lbs for C

[Sayonara]

Perhaps it means "five to fifteen parts of A", and you have to use cunning equations and such to work out the actual ratio.

[mossoi]

Well for the latter the parts would be 850, 1050 and 7 respectively because that is the ratio expressed using the lowest possible integers.

 

As for the former. I have no idea other than to suggest that the compostion may be made using several different ratios. For example concrete has different ratios of sand, cement and pebbles depending on the strength required. 1 part sand to 1 part cement to 1 part pebbles is as much concrete as 2 parts sand to 1 part cement to 1 part pebbles.

 

I must warn you though, I'm not a chemist so there may be a more specific definition I'm missing. I'm just using the general idea of parts to a composition. If the first example goes on to ask how do you determine the amount of A, B or C then it's pretty likely that the composition can be of various ratios.

[senexa]

Parts is an old expression used for any equation or recipe using measurement. It equals "X".

 

So if you have 500 lbs of A, 400 lbs of B and 100 lbs C, you can convert it to

 

5 parts of A + 4 parts of B + 1 part of C, with 100 pounds being the "part".

 

This is used a great deal in old chemical formulas, cooking recipes and medicinals.

[dryan]

Wait a second, what if they meant 5-15 parts A by volume. Uh oh, now we're in trouble.

[mossoi]

I think one would have to deduce the units from the rest of the example or question. Otherwise it's completely useless and probably why it's dropped out of favour.