Update:

this lab is about replacement of hydrogen byn magnesium. its basicly adding acid to water in the eudiometer then fill it with water, and watch the coiled magnesium react with it.

BUT the lab questions about procedure driving me CRAZY!!

1) is the acid now cencentrated or dilute after the reaction with coiled magnesium?

Update 2:

2) after reaction stopped, adjust the tube until the water lecels inside/outside are same. add water if necessary. but if this adjustment is not possible with the apparatus you h

Update 3:

are using, what computation can you carry out that will yield the same result?

3) read the colume of hydrogen l iberated/ take temp, and assume its the temp. of hydrogen gas. why is this a rasonable assumption?

Update 4:

also, i used the density of hydrogen gas times by volume of H2(corrected to stp). is that correct?

THANK YOU SOOO MUCH

Relevance
• david
Lv 7
5 years ago

1) is the acid now cencentrated or dilute after the reaction with coiled magnesium? ----- it is more dilute after the reaction

2) after reaction stopped, adjust the tube until the water levels inside/outside are same. add water if necessary. but if this adjustment is not possible with the apparatus you are using, what computation can you carry out that will yield the same result? ------ PV = PV ... use a Boyle's Law calculation to correct the pressure in the tube to atmospheric pressure ... remember to convert the difference in height inside vs. outside the tube which is a water level into a mercury height difference.

3) read the volume of hydrogen liberated/ take temp, and assume its the temp. of hydrogen gas. why is this a reasonable assumption? ------ Water can absorb a lot of heat. The gas was created inside the water, so the water absorbed heat of the reaction .. so they should be the same temp.

4: also, i used the density of hydrogen gas times by volume of H2(corrected to stp). is that correct? ---- to find what? density = m/V ---- m/V X V = m ,,, If you are trying to find the mass of hydrogen gas produced then this would be correct. If you were told to find something else, then this would be wrong. Where did you get the density? Is this a density for this specific temp. and pressure? If not, then this would not be correct.