Monday, September 24, 2012

SPM Chemistry Tips #3 STATING VARIABLES - How to identify it from questions?


I think most of form five students have finish their trial examination by now:)
How is your Chemistry mark students?  Hope that the mark gives good motivation to you as the SPM 2012 examination is coming.

So, during marking my students answer sheets, I've found out that there are still students unable to write and stating variables correctly.  As you know, In SPM Chemistry Paper 3, stating variables is one of construct that will be asked.  This type of question will bring you 6 to 9 marks all together.

In order to solve these students weakness, I've shared some tips.  If you think this tips are applicable, then you are welcomed to use this tips.

to apply this tips you NEED a red, blue and green pen
[you may use your highlighter too but must be in different colour]

  1. Read the question carefully.
  2. Now, UNDERLINE using Red pen the variable that changes in the experiment ---> MANIPULATED VARIABLE
  3. UNDERLINE using Blue pen the variable that being observed in the experiment --> RESPONDING VARIABLE
  4. UNDERLINE using Green pen the variable that being fixed in the experiment --> CONSTANT VARIABLE
  5. Write the identified variable specifically to the experiment being done.
Now, let us try to do it using this example.

EXAMPLE 1 - Paper 3 Essay [SPM TRIAL 2012 - Perak]

MANIPULATED VARIABLE : Type of metal coiled to Iron nail
RESPONDING VARIABLE : Presence of blue spot (that shows corrosion of Iron nail)
CONSTANT VARIABLE : Iron nail / Jelly solution mixed with potassium hexacyanoferrate (III) solution

EXAMPLE 2 - Paper 3 Structure [SPM TRIAL 2012 - Kedah]

MANIPULATED VARIABLE : Type of acid / hydrochloric acid, ethanoic acid
RESPONDING VARIABLE : heat of neutralisation
CONSTANT VARIABLE : volume and concentration of sodium hydroxide solution

Now, you can try this tips in your Paper 3 practice... Selamat Mencuba.

1 comment:

  1. what is the function potassium hexasianofrate (III) solution??