Science Infoblog » acids http://johnwest.edublogs.org assisting learning inside school from the outside.....JOHN WEST HOD SCIENCE Thu, 19 Nov 2009 20:33:25 +0000 http://wordpress.org/?v=2.8.2 en hourly 1 Motion and graphs, acids and bases, more from Shelley Dudley’s class http://johnwest.edublogs.org/2009/07/30/motion-and-graphs-more-from-shelley-dudleys-class/ http://johnwest.edublogs.org/2009/07/30/motion-and-graphs-more-from-shelley-dudleys-class/#comments Thu, 30 Jul 2009 08:44:24 +0000 john west http://johnwest.edublogs.org/?p=186 Year 10 students studying  NCEA level science this year have made a number of 5 minute tutorials that cover aspects of their course. Have a look at them. The first video deals with acids and bases.

The second video covers motion and distance time graphs. Do you find these tutorials useful. Why don’t you pick a topic with some friends and make your own video.

]]> http://johnwest.edublogs.org/2009/07/30/motion-and-graphs-more-from-shelley-dudleys-class/feed/ 0 Year 11 chemistry:balancing chemical equations, reactions of metals and acids http://johnwest.edublogs.org/2009/03/26/year-11-chemistrybalancing-chemical-equtions-reactions-of-metals-and-acids/ http://johnwest.edublogs.org/2009/03/26/year-11-chemistrybalancing-chemical-equtions-reactions-of-metals-and-acids/#comments Thu, 26 Mar 2009 10:29:34 +0000 john west http://johnwest.edublogs.org/?p=153 Chemistry has its own language with words and sentences.

To a chemist the words are chemical formulae. When chemical formulae are joined together in a sentence we call this a chemical equation.

Hydrogen and oxygen mixtures explode when lit. In a test tube this explosion is heard as a “pop”. We call the test for hydrogen “the pop test”

The space shuttle is launched into space with three main engines. Each engine produces 1.8 Meganewtons of thrust. The engines are powered by liquid hydrogen and oxygen fuel stored in the large central rust coloured tank.

The space shuttle is blasted into space on the back of a mega “pop test” The two tanks on either side of the shuttle are solid fuel boosters.

Hydrogen molecules and oxygen molecules react with each other to form water molecules. A chemist rewrites this sentence as a word equation

hydrogen + oxygen —–> water

Chemists use chemical formulae instead of words. Finally chemists need to count the numbers of atoms involved. We need to have the same numbers of atoms after the reaction that we had at the start.

When we do this we end up with a fully balanced chemical equation. As far as NCEA level 1 is concerned here are the steps.

  • word equation…..achievement
  • with chemical formulae……merit
  • a fully balanced chemical equation…..excellence

Check out the video to see how we get a fully balanced equation for the “pop test”

try balancing the equations that describe metals reacting with acids.

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