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#1
05-22-2001, 05:22 AM
 gadgetgirl Guest Join Date: Apr 2001 Posts: 270
We are having a trivia night at work soon so everyone in the office has been spouting off heaps useless knowledge. (some right, some, not so right)
Anyway, one of the guys asked my, "Which weighs more, a truck load of Pepsi, or a truck load of diet Pepsi?"
I said that they weigh the same and he said, "Nope, the regular Pepsi weighs more than the diet Pepsi because of the weight of the sugar in the regular Pepsi."
Um, sound a bit fishy to me...Isn't there some sort of sweetener in diet Pepsi? And how does the weight of the sweetener in the diet Pepsi compare to the sugar in the regular Pepsi?
Can anyone conferm or deny this thought?
And I'm a Coke girl myself, Pepsi is too sweet for me anyway.
#2
05-22-2001, 05:29 AM
 Mangetout Charter Member Join Date: May 2001 Location: England Posts: 57,339
This is probably true, sugar syrup is considerably denser than water sweetened with artificial sweeteners.

(it's possible to add and dissolve certain things in water without significantly increasing the volume; we did this at school with water and salt - the salt goes into solution, but the volume of the water isn't increased, may be the same for sugar, but I don't know)
#3
05-22-2001, 05:35 AM
 AgentofEvil Guest Join Date: Apr 2001 Location: New Zealand Posts: 26
You can do it with water and meths and end up with less volume than what you started with. Add fifty mLs of each and you'll get 97mL!
#4
05-22-2001, 08:27 AM
 Dragwyr Charter Member Join Date: Oct 1999 Location: Right behind you!!! Posts: 3,941
It seems to me that this could be answered by knowing how pepsi and diet pepsi are measured into their respective containers: By weight or by volume. If it is by weight, then they would weight the same (because each can would have the same amount by weight). If it is by volume, then one truck would probably be heavier than the other because equal volume doesn't necessariily mean equal weight.

I don't know that regular sugar would weigh more than it's sugar substitute counterpart, but one would have to be heavier than the other.
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#5
05-22-2001, 08:48 AM
 Mangetout Charter Member Join Date: May 2001 Location: England Posts: 57,339
I would imagine that since the cans are marked up as containing 330ml, that there is a legal obligation to fill them by volume rather than weight (within tolerances of course)

Sugar substitiutes are very much more compact than sugar itself; one nutrasweet tablet is very much smaller and lighter than the spoonfull of sugar to which it is equivalent; I suspect that the artificial sweeteners used at industrial scale are even more compact, as the tablets for tea/coffee probably contain fillers to make them a manageable size.
#6
05-22-2001, 09:52 AM
 Lance Turbo Guest Join Date: Aug 1999 Location: Asheville, NC Posts: 2,681
This shouldn't be too hard to find the definitive answer to. Doesn't anyone have access to a can of Pepsi, a can of Diet Pepsi, and a scale.

My guess is that they are pretty close to being the exact same weight.
#7
05-22-2001, 10:31 AM
 Shiva Guest Join Date: Sep 2000 Posts: 551
Quote:
 Originally posted by Lance Turbo This shouldn't be too hard to find the definitive answer to. Doesn't anyone have access to a can of Pepsi, a can of Diet Pepsi, and a scale. My guess is that they are pretty close to being the exact same weight.
They'd be very close to being the same weight. In fact, the variation in fill level would be greater than the difference in density.

We need a volunteer to carefully measure out Xml of both Coke and Pepsi and weigh those samples.

Any Lab Rats out there in Doperland?
#8
05-22-2001, 10:35 AM
 Mangetout Charter Member Join Date: May 2001 Location: England Posts: 57,339
the difference may be slight for a single can, but the OP referred to a truckload; even the slightest variation in density between the two types would certainly have a measureable effect when scaled up to this extreme.
#9
05-22-2001, 07:06 PM
 robby Charter Member Join Date: Dec 2000 Location: Connecticut, USA Posts: 5,130
The difference in density is easy to demonstrate. When I taught chemistry, and covered "density," I put a can of regular Coke and a can of diet Coke into a large glass beaker full of water. Guess what happens?

The regular Coke sinks; the diet Coke floats.

(For those wondering how the diet Coke could possibly float in water, meaning that its average density is less than that of water...don't forget the air space in the can.)
#10
05-23-2001, 02:07 AM
 honkytonkwillie Guest Join Date: Apr 2000 Location: Anchorage Posts: 606
This is too easy.

Aspartame is made of phenylalanine and aspartic acid which are amino acids which have ~4 calories per gram. Sugar and other carbohydrates also have ~4 calories per gram. The really cool trick is the fact that aspartame is about 200 times sweeter than sugar, so it takes 200 times less Nutrasweet to achieve a comparable sweetness for a given volume of beverage.

How many calories in a can of Pepsi? I don't know since I drink Diet Coke exclusively. I'd wager 160 calories in a 12 oz. can is reasonably close. Assuming all the calories in Pepsi come from sugar, that's a whoppin' 40 grams of sugar per can. Dividing that by 200 yields an estimate of 0.2g (200mg) of aspartame for a can of Diet Pepsi.

So, yeah. A truck load of Diet Pepsi should be lighter.

Someone will surely ask for a cite.
#11
05-23-2001, 02:54 AM
 sailor Registered User Join Date: Mar 2000 Location: Washington dc Posts: 16,441
OK, something I know something about. Regular soft drinks are quite a bit more dense. Two parameters measured and controlled very carefully during the manufacture of carbonated beverages are carbonation and sugar content. Sugar content is measured in brix. Brix = 10 means 10% sugar in weight which results in a specific gravity of about 1.04
The way to measure brix is to measure specific gravity and then calculate brix from there

Artificial sweeteners are *much* sweeter than sugar and the amounts used are miniscule compared to sugar. You cannot use a densitometer and keeping the concentration constant is much more difficult.

So, yes, a diet drink has a specific gravity marginally over 1 while a regular drink will be about 1.04

Since they are canned by volume and not by weight, yes, a truck loaded with diet drinks would weigh a bit less.

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