Monday, December 13, 2010

Bubbles

Today, we did the Molar Volume Lab. Here's what happened.
First, we cut a piece of magnesium in half and measured its length because we would not be able to find the mass on a scale. Magnesium is .01085 g/cm. Our piece of magnesium was 2.5 cm. Then, we tied a piece of copper wire around the magnesium ribbon so that the magnesium would not float around in the eudiometer. (http://www.flickr.com/photos/hc1011/5258241891/) The eudiometer is a gas collection tube, measuring gas by water displacement. We poured 10 ml of HCl and 100 ml of water into the eudiometer. The temperature of the tap water was 21.3°C. Room temperature was 22.2°C and the barometric pressure was 30.11 inHg (we have to convert it to mm). We put the cork attached to the copper wire and magnesium at the open end. We then flipped the eudiometer over, safely and carefully, and put the cork end into a beaker with water and clamped the eudiometer so it would stay up. We watched as the magnesium reacted with the HCl and created bubbles of hydrogen. (http://www.flickr.com/photos/hc1011/5258850050/) Slowly, the water was going into beaker and leaving space at the top of the eudiometer. While we waited for the reaction to finish, we recorded the room temperature and the barometric pressure at room temperature. Once the reaction stopped bubbling, we took the eudiometer to the fume hood and measured the volume of the gas. The volume of the gas was 27.4 ml of hydrogen. (http://www.flickr.com/photos/hc1011/5258850358/)
This lab is due Wednesday. Our test for this unit is Friday. Sorry about the pictures, they won't show up. So I included the links to them.
This has been Kaitlyn. (with a Y!) Thank you, thank you very much. :)
The next scribe will be Matt P!

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