Friday, December 11, 2009

Chem Class- December 11, 2009

Today we got our tests back! We hope everyone did well.
  • We got a new outline for our new unit. We are are going to be learning about chemical reactions!
  • Mr. D showed uss a small lab with hydrochloric acid (PH of -1)
      • He added bromothemal blue and the hydrochloric acid turned a light yellow colour
      • Then he added ammonia to the mixture. The top of the mixture turned blue. He added more ammonia and the blue stayed on top of the acid.
  • Mr. D turned on the gas valve and we found out that someone hadn't turned it off. It stunk really bad!
      • If he lit a match, there would be an explosion
  • Next, he showed us another experiment where he mixed in potassium iodie with iron iodide. It made the mixture turn yellow
  • He also got out the match and burned magnesium. We saw a spectacular light, but were not supposed to look directly at it. Apparently this was how fireworks were made.
  • Finally, he dipped a piece of paper in salt water and alcohol and put it through the bunsen burner. Flames appeared for a short instant but it did not burn the paper. The alcohol was burning.



<---burning magnesium


Signs of a chemical Reaction: colour change, property change, energy change, temperature change, precipitate forming, gas production, heat and light produced...

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