Measuring is one of the important skill in chemistry. In the chemistry laboratory, it's common to find various apparatus e.g.buretthe, stop watch, voltmeter, thermomether, etc.

Measuring is one of the scientific skill included in Paper 3 Chemistry SPM. After going through different exam papers, examples of apparatus that I have noticed are as follows:
  • stop watch(2003, 2008)
  • Ruler (2003)
  • Electronic balance(2004)
  • Thermometer(2005, 2006, 2007)
  • Buret
  • Voltmeter
In order to score in this section, remember :
  • write the value of the measurement according to the accuracy of the apparatus. E.g. buretthe reading has 2 decimal places.
  • All the values must be consistent and with units.E.g. the unit for buretthe reading is cm3. Please ensure all reading recorded with 2 decimal places.
Any doubts with the measurement, please leave your comments here. All the best!


Question Analysis for Paper 2 & Paper 3 Trial SPM 2019 from Different States

Thousands thanks to
  • Hanna & Hanni who have contributed their analysis for Trial Kelantan paper.
  • Dhiya who has sent her analysis for Trial Negeri Sembilan paper
  • Anis Adibah who has comments on Trial Perlis paper. (Incomplete analysis on Paper 2)
  • Syafiqah, Nazirah and Shakina who have posted their comments on Trial Kedah paper
  • Liyana Yahaya and Rohiza comment on Mallaca Trial Paper
  • Sofea and Syazwani  comment on Selangor Trial Paper
  • Lisa and Najihah sent their comments on Perak Trial Paper.
The analysis will be updated from time to time...


Transfer of Electron at A Distance

Students find difficulties in answering question related to this topic.
  • which electrode is the negative terminal/positive terminal?
  • mark the flow of electrons on the circuit
  • which one is the oxidized substsance/releases electron/reducing agent?
  • which one is the reduced substance/gain electron/oxizing agent.
  • write half equation to show the reaction occur at each electrode
  • write overall ionic equation for the reaction that occur in the U-tube
  • Write observation.

Actually a student only need to remember some examples of oxidizing agent and reducing agent. Some examples of oxidizing agent and reducing agent are as follows

Lets take an examples when iron(II) sulphate solution and bromine water are used.

iron(II) sulphate solution is the reducing agent.

  • iron(II) ion loses electron to form iron(III) ion.
  • So, iron(II) ion is the oxidized substance.
  • As electrons is produced, the electrode that dipped in the iron(II) sulphate solution is negative terminal
  • electrons flow from this eletrode to another one through the external circuit.
  • Observation: the green iron(II) sulphate solution turn yellow/brown
  • Half equation: Fe2+ --> Fe3+ + e-

Bromine water is the oxizing agent.
  • electrode that dipped in bromine receive electron from the external circuit.
  • So, this electrode is the positive terminal.
  • Bromine gain electron, so bromine is reduced to bromide ion.
  • So bromine is the reduced substance.
  • Half equation: Br2 + 2e- --> 2Br-
  • Observation : the brown bromine water turn colourless.

As writing overall ionic equation, a student just need to add both half equation together.

Half equation 2Fe2+ + Br2 --> 2Fe3+ + 2 Br-

Try different questions to see how much you apply the tips given. All the best!

Photos shown my students were working in groups to set up apparatus to study transfer of electrons at at distance.



Concept of moles is an important concepts in chemistry. Students learn the basic concepts in Chapter 3 Chemical Formulae and Equation during form 4. Later, they relate the moles concepts with molarity of a solution in Chapter 7 Acids and Bases and Chapter 8 Salts.

During form 5, students are expected to apply the concept well in various numerical problems in Chapter 1 Rate of Reaction, Chapter 4 Thermochemistry.

Some common wrong concepts that I have come across:
  • students thought that the moles is the same with molarity.
  • they thought that volume refer for both solution and gas.
Plese my dear students, please study the relationship above thoroughly. Whenever come across any question related to this concepts, understand the questions and substitute the value given in the equation correctly.

Form 4 Final Examination SBP Year 2008

Dear form 4 students, please download  this 2008 final exam paper and have a look.

Perhaps it will help you
  • to have a clearer picture about the examination format
  • to identify which areas you are still weak in.
Any doubts about the foming finals, you're always to post  your comments here. 

All the best and enjoy your Deepavali holidays.

The picture is taken from http://annaleeblysse.blogspot.com/


Trial Chemistry Selangor 2009

Paper 3

Dear visitors, please leave comments about the questions after going through the papers. You're welcomed to leave any doubts/querries about the questions. Thanks.