[bigbenz]

Hi, so I did an experiment earlier. And these are the steps I did:

1. I placed 10.0 mL of 6.0 M HCl into a eudiometer partially filled w/ distilled water.
2. Add water to fill the eudiometer to the brim.
3. I covered the mouth of the eudiometer with a finger and invert it into a glass that is 2/3 filled with water
4. I inserted folded Mg ribbon into the eudiometer
5. And I recorded the Volume of the enclosed gas, the height difference between the water levels inside and outside the eudiometer, and the temperature of the water outside.

So let's say I accidentally dropped the magnesium ribbon inside the acid-filled eudiometer. Bubbles already started forming before I inverted the eudiometer inside the water-filled beaker. How will this affect the calculated experimental mass of the magnesium ribbon? Will the calculated experimental mass of Mg ribbon increase? decrease? will it be indeterminate? or no effect?

[Hunter2]

What do you think, if you did not catch the whole amount of hydrogen, with you result.

[billnotgatez]

There is a suggestion that often applies to this kind of situation.

1. Start by writing a balanced chemical equation.

[billnotgatez]

...
3. I covered the mouth of the eudiometer with a finger and invert it into a glass that is 2/3 filled with water
...

Did the bubbles start before or after you covered the opening with your finger?
Can we assume that no gas escaped from the eudiometer?
or
did some escape prior to covering?

Is this just a thought experiment (test question) or an actual event?