Science Infoblog » NCEA Level 2 Chemistry 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 NCEA Level 2 Chemistry: rates of reaction, strong and weak acids http://johnwest.edublogs.org/2009/08/18/ncea-level-2-chemistry-rates-of-reaction-strong-and-weak-acids/ http://johnwest.edublogs.org/2009/08/18/ncea-level-2-chemistry-rates-of-reaction-strong-and-weak-acids/#comments Mon, 17 Aug 2009 23:24:11 +0000 john west http://johnwest.edublogs.org/?p=218
Rate of reaction Research project

 

mass loss

mass loss

When a gas is given off during a chemical reaction the rate can be measured by weight loss on a pan balance.

Decide how you will compare the rates of reaction between 2.0 and 1.0 mole per litre hydrochloric acid with marble chips. Compare rates of reaction between 2.0 moles per litre hydrochloric and ethanoic acids with marble chips.
Gather data  (use 50.0 ml samples  of the acids for your investigations) and plot your results graphically.
 A follow up investigation might look at the pH of sequentially diluted solutions of ethanoic and hydrochloric acids (2.0, 1.0, 0.1, 0.01, 0.001 moles per litre)
 
Research project write-up.
 
Do a brief experimental method and graph you results using a spreadsheet
Present your results on word document or powerpoint. Discuss your findings in terms of :
  • species in solution
  • observed rates of reaction
  • total mass of carbon dioxide released (starting with the same amount of acid)
  • the strengths of the acids and equilibrium concentrations
  • the pH of both acids at different concentrations

As a follow up to your research track the pH changes that occur during these reactions and discuss.

]]> http://johnwest.edublogs.org/2009/08/18/ncea-level-2-chemistry-rates-of-reaction-strong-and-weak-acids/feed/ 0 NCEA level 2 Chemistry: Structure and bonding Oscars http://johnwest.edublogs.org/2009/07/01/ncea-level-2-chemistry-structure-and-bonding-oscars/ http://johnwest.edublogs.org/2009/07/01/ncea-level-2-chemistry-structure-and-bonding-oscars/#comments Tue, 30 Jun 2009 20:59:47 +0000 john west http://johnwest.edublogs.org/?p=184 The task:

Present a demonstration to fellow students outlining why ionic compounds conduct electricity when molten or in aqueous solution.

Preparation time:

1 lesson to research material and plan roles to be undertaken by group….. cameras…. action….. roll…. take 1.

This is an opportunity for you to demonstrate your learning…….it also shows me where I need to do better. Sodium ions don’t get discharged from aqueous solution…..apologies for any confusion I may have caused here!

]]> http://johnwest.edublogs.org/2009/07/01/ncea-level-2-chemistry-structure-and-bonding-oscars/feed/ 2 Structure and bonding : Pottery and the chemistry of silicates http://johnwest.edublogs.org/2009/06/29/level-2-chemistry-pottery-and-the-chemistry-of-silicates/ http://johnwest.edublogs.org/2009/06/29/level-2-chemistry-pottery-and-the-chemistry-of-silicates/#comments Mon, 29 Jun 2009 08:18:27 +0000 john west http://johnwest.edublogs.org/?p=183 Art is often chemistry that looks good. Your mission should you chose to accept it is explain changes in the properties of clay as it is allowed to dry, bisc fired then given a final firing and glazing.

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