Friday, May 10, 2013

Chemistry: How to answer paper 3 question

Assalamualaikum! Hye! 

a) Statement of the problem: It always must be a question and ended with question mark. Read the question well and you will find it in the hint in the question. Start your statement of the problem with ‘How does manipulated variable affect responding variable?’ or ‘Does increasing/decreasing manipulated variable increase/decrease the responding variable?’

b) Aim of experiment: It always must be a statement and ended with full stop. Start your aim of experiment with ‘To compare … / To investigate … / To study …

c) All the variables: List out all the variables and separate each variable in the following sequence.

Manipulated variable: (axis-x values)
Responding variable: (axis-y values)
Constant variable:

d) Statement of the hypothesis: It always must be a statement and ended with full stop. ‘The manipulated variable, the higher/lower/increase/decrease responding variable’

Important note: Must follow the sequence (always start with manipulated variable and follow by responding variable).

e) List of substances and apparatus: Always separate substance and apparatus even though this is in one section. Must list everything completely to get 3 marks!

Substances: (the same meaning with materials in PEKA experiments)

Important note: Solution: try to give the concentration of the solution (always in the range of 0.1 – 1.0 mol dm-3) and concentrated solution (>1.0 mol dm-3)

0.1 mol dm-3 of hydrochloric acid
0.5 mol dm-3 of nitric acid
1.0 mol dm-3 copper(II) suphate solution
0.5 mol dm-3 NaOH, zinc powder …
Apparatus: try to list as complete as possible (everything that can be reused in the experiment)

Stop watch
measuring cylinder
retort stand
conical flask
filter funnel
tongs …

f) Procedure of the experiment: This is the hardest part to get full marks (3 marks). You need to write the procedure as complete as possible which means all steps are to be written in detail. Berry Teacher would recommend the sentence should be written in passive form sentence (same in PEKA) and it can be present or past tense (no penalty). And try to uniform it. From the previous SPM Paper 3 record, there is no penalty if you write in active form sentence but not in PEKA report!

g) Tabulation of data: This is the easiest part to get one mark, as long as you draw a table (empty table / box), you will be given at least one mark. Remember to write unit in the manipulated variable column and responding variable column!

Goodluck! Bittaufiqiwannajah! :')

No comments: