Sunday, November 28, 2010

SKEMA Kertas 3 : PAT Tingkatan 4

*Jawapan yang disediakan ini adalah yang dapat memberikan SKOR 3 sahaja.

(a) Time(min)       The rise sucrose level(ml)
         0                            0.0
        10                           4.5
        20                           9.5
        30                           9.9

(bi)  Observations - Sample Answers :
      1-The first 10 minutes, the sucrose solution level is 4.5ml.
      2-At the 20th minutes, the sucrose solution level is 9.5ml.
      3-At the 30th minutes, the sucrose solution level is 9.9ml.

(bii) Inference - Sample Answers :
      1-At the 10th minute, water molecules diffuse through the 
          Visking tubing due to osmosis process.
      2-At the 20th minute, water molecules diffuse through the 
          Visking tubing due to osmosis process.
      3-At the 30th minute, water molecules diffuse through the 
          Visking tubing due to osmosis process.

(c) *same answer as (a); in table form

(d) Variables :

     Variables                Particulars to be implemented
     Manipulated :     The reading are taken at the different intervals//
     Time                  The reading are taken at 10 minutes intervals

      Responding :      Measuare and record the rise in the sucrose 
      The rise in         solution level by using the scale on the glass
      the sucrose        tube.
      solution level

     Constant :           Using the same concentration of sucrose
     Sucrose              solution //
     concentration//
     Volume of         Using the same volume of distilled water
     distilled water  
    
(e) Hypothesis - Sample Answers :
     1-The longer the time taken, the higher the level of sucrose
         solution(in the scaled glass tube)
     2-The shorter the time, the higher the level of sucrose solution 
        (in the scaled glass tube)
     3-If the time taken is shorter, the level of sucrose solution in the 
        scaled glass tube is less.

(f) Interpreting Data - Sample Answers :
    [The level of sucrose solution increases with time.]
    This is [because water molecules from outside the Visking tubing 
    diffuse through the semi permeable Visking tubing] [by osmosis 
    process.]

(g) Predicting - Sample Answers : (either answer 1 or answer 2)
     1-[The level of sucrose solution in scaled glass tube increases
         more than 9.9ml] because [water molecules diffuse through
         the semi-permeable Visking tubing] [by osmosis process.]
     2-[There is no increase in the level of sucrose solution in the 
        scaled glass tube] because [the dynamic equilibrium has
        achieved.] The level of sucrose solution in the scaled glass
        tube is 9.9ml [because the net movement of water molecules
        in and out of the membrane is the same.]

(h) Defining by Operation - Sample Answers :
     1-Osmosis is a process where water molecules enter the Visking 
         tubing at the 10th minute and the level of sucrose solution in 
         the scaled glass tube is raised at 4.5ml.
     2-Osmosis is a process where water molecules enter the Visking 
         tubing at the 20th minute and the level of sucrose solution in 
         the scaled glass tube is raised at 9.5ml.
     3-Osmosis is a process where water molecules enter the Visking 
         tubing at the 30th minute and the level of sucrose solution in 
         the scaled glass tube is raised at 9.9ml.

(i) Classifying :
  
       Material                       Picture
  Distilled water                       C
 15% sucrose solution             A
 20% sucrose solution          B and D

 

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