Why closed bottle change its weight when I put effervescence tablet?
I use several shape, several type of material (glass, metal, plastic), I use two different balances with 0.01g of accuracy. I put oil on gasket, and put upside down (like that I can see if water escape). But always it's the same result, when I put one, two or more effervescence tablets, the weight decrease:
one tablet => -0.03g
two tablets => -0.06g
three tablets => -0.09g
Sure the difference is not big. But if I put an object without effervescence tablet, the weight is always the same (move sometimes +0.01 or -0.01g but never more). The time for decreasing is about 2 minutes so it's not enough for change something from temperature I think especially with glass container.
So, maybe someone has done this experimentation before and know where is my error ? Or maybe someone can test and try this experimentation ?
<PERSON>: "Recall that the air density is about 1.3 grams per cubic centimeters", you're sure ? it's not 0.0013 ? Yes, I have the same values for glass (2 mm of thickness and one of 3 mm of glass) with a metal cover of 0.8 mm of metal. I done about more than 100 measures. 1018
After 2 minutes, the tablet is full dissolved in water and weight move very few after (-0.01g next 2 minutes) but never more.
Maybe I found: when bubbles move up in water, they have gas in it (CO2), this gas move up with a speed, so there is a quantity of movement, the weight losses is the sum of mass of bubbles multiply by speed. Like quantity of movement is conserved, the weight don't change.
It's possible to use the formula of <PERSON>: force=2mv if top speed is 0.25 m/s the weight losses is 20.3/10000.25/10 = 0.015 g with 0.3 g of CO2, image show speed that I found on Internet. If it's that, the weight must change with a ball full of air (ping-pong ball) in water. But the CO2 in a tablet is very powerfull, 0.3g give 0.187 liter of CO2, even the ball move faster the volume is not great in a bottle. The ball must be down before close the container. And the gas must relax when the ball reached surface.
Is it possible it is the rotation of Earth that change the pressure in water due to the centripetal forces ? This give -0.03N for each kg of water.
Good day 439