CIE A-level Chemistry Paper 3 Tips

Chemistry practical is the hardest practical exam out of the three sciences. Two hours are really too short to finish the paper. So, time management is really significant for this paper. 


Qualitative Analysis

1. Titration

Titration is a very common questions that will be asked. Before you start conducting the experiment, read the questions carefully. Then, draw tables for you to record your readings.
Normally they will want you to record a rough titration and two accurate titration. For the table, you need three rows, which is :

-Final burette reading/ cm3
-Initial burette reading/ cm3    
-Volume of __ added /cm3

Always remember the units! Always put initial burette reading as 0.00. Value of the two accurate titration must be at most 0.10 difference only!


The next question will most likely be, find the suitale value of ___.
Since you have two readings for ___. Just calculate the mean to get the answer.


They will also ask you to calculate the mole, concentration or volume of the solution. So, what if they give you g dm-3 instead of mol dm-3? How are you going to calculate the mole?

-If they give you g dm-3 and also g mol-1 which is the relative molecular mass, you can find the concentration, mol dm-3 by dividing. Once you get mol dm-3, you can calculate the mole.

Always, always use ratio to calculate. For example, they will ask you to find the number of mole of FA1 in 250cm3. If FA1 has 0.01 mole in 25 cm3,  FA1 then has 0.1 mole in 250cm3.

250/25 x 0.01 = 0.1 mol

Maximum error in volume run from the burette, 
0.05 x 2 = 0.10 cm3

Maximum percentage error for burette,
0.10/(Volume of solution used) x 100 %

Maximum error of mass, 
0.01/2 = 0.005

Maximum percentage error of mass,
(2 x 0.005) / (mass of ___) x 100%


**Always, always, always remember to put your answer in 3 significant figure!

2. Graph

-Draw the x-axis and y-axis and label it. Give units for each of the label. 
-Use suitable scale for your graph, like factors of 2, 5 and 10.
-The graph can start from other numbers instead of 0.
-The plot must be smaller than the small box. 
-Graph must be larger than half of the graph paper.
-Normally there will be 2 lines; they can be straight line or curve line, depends on the question.

3. Experiment with heating

If the question ask you to conduct the experiment with 2 different masses of  ___, you will need three column for your table because you need to record two different readings.

-mass of tube + ___ /g
-mass of empty tube /g
-mass of tube + residual /g 
-mass of residual /g
-mass of water lost /g


If the questions only want you to conduct the experiment with only 1 mass, you only need two column as you only have one type of readings to be recorded. However, you need to draw three row next to 'mass of tube + residual /g' to record the readings three times. This is because you need to heat the tube for at least 3 times to get the residual with the maximum water lost.  

The last reading of mass of tube + residual with be used in your calculation. 

the formula Q = mc T is important. 






Qualitative analysis

-Use the qualitative analysis notes wisely! If your answers are anything related to the reactions of aqueous cations, reactions of anions and tests for gases, make sure to copy every words from the qualitative analysis notes to the answer spaces.

-When your answer has gas in it, make sure you write out the name of the gas too. For example, DO NOT write gas turns damp red litmus paper blue, but write NH3 gas turns damp red litmus paper blue. 

-For any colour change, make sure you indicate the initial and final colour. Do not just write the final colour change.

-If precipitate is seen, note down the colour and solubility (refer to qualitative analysis notes!)

-If gas bubbled are formed, it means there is gas released. The gas test can be found on the qualitative analysis notes. 

-Write down if you see any efferverscence occurs. 

Frequently asked questions...

- (heating) Why total volume of solution used was kept constant in each experiment?
A: change in volume give difference change in temperature for same energy produced.

-(heating) How to ensure all water of crystallisation had been removed?
A: repeat the heating, cooling and weighing process for a few time until a constant mass is obtained.

-(involve metal) Stat the observation which confirm sulfuric acid is in excess.
A: magnesium ribbon dissolves completely in sulfuric acid.

-(involve metal) Which temperature change has hgiher percentage error?
A: test with shorter magnesiu ribbon.

-(If asked to compare two reactions) Reaction 1 is more accurate. Why is reaction 2 less accurate?
A: lower enthalpy change and higher percentage error.

-What is the effect on percentage error in mass if greater mass is used?
A: percentage error in mass increases.

-How repeating experiment would lead to greater reliability?
A: to show consistent result / to eliminate anomalous result

Recently questions with this type of experiment is very popular. You can find it in May/June 2016 paper as well as the recent one, Oct/Nov 2016 paper.

What should you record for your table then?

Mass of container + (chips used) /g
Mass of container /g
Mass of (chips used) /g 
Final volume of gas collected /cm3

The gas collected is CO2.


They also like to ask about inaccuracy and want you to explain a modification to help reduce the difference in volume. 

I: Some CO2 evolved dissolved in the water (less volume than expected)
M: Use other substances like oil which CO2 is not soluble.

I: CO2 lost before the bung replace
M: arrange the marble chips in flask so mixing is carried out after bung replaced/ use larger lump of solid

I: delay in starting stopwatch (greater volume than expected)
M: ask for assistance

CIE A-level Physics Paper 3 Tips

Physics is a tough subject for me. I always have hard time with Physics. The only paper that can save me is probably Paper 3. Yea...maybe, I don't know.

So, I'm going to share a few tips of it.


First section
Basically, this section is all about table and graph.

For table:
-Make sure column of heading is correct.
-Each column heading must contain an appropriate unit.
-Significant figures of each column are correct.
-Values measured are in range.

For graph: 
-x-axis and y-axis have appropriate scale and labels.
-plots are correct and must the 'cross' must be smaller than the little box of the graph paper.
-line of best fit.
-good quality of the graph

After you have draw your graph, you can obtain gradient and y-intercept from it. Make sure you give an appropriate unit for your gradient and y-intercept.

For the last part of this section, they wil give you a related equation and will ask you to calculate the values of ___ and ___. Use the formula Y=mX+c to find the values.



Second section

If you see there are two mark boxes beside one measuring questions, measure it two times and find the average.

For the question, estimate the percentage uncertainty of x, use the formula,

(x1 -x2)/xavearage x 100

To justify the number of significant figure you have given for ___,
-___has __significant figure based on (eg. t and d)


To support the suggested relationship, you have to use the k values that you have calculated.
if k1<k2

(k2 - k1) / k1  x  100


Lastly, there will be source of uncertainty or limitation and the improvements that could be made in the experiment. I will list out a few general one. 

• 2 sets of measurement are not enough to draw a valid conclusion

         -repeat to obtain more measurements and plot a graph to obtain more k value

•   Time is too short when the object drops

         -Use a longer tube to increase the distance / take video with timer and replay to view it frame by            frame.

• x has to be taken at eye level on the point of release, but it is hard to determine the point of ___

         -Keep eyes parallel to the horizontal level of metre rule to predetermine the potential location of            x value.

• It is difficult to judge the centre of object 

        -Measure the tp and bottom of the object and calculate the average then mark the centre.

• Force of my finger to push object is different

        -Use a mechanical hand so that equal forces are exerted upon realease.

• Difficulty in deciding the toppling point of the object

       -Move by increment with newtonmeter and tilt until F=0

•  Difficulty to measure length of wire as the clips have width and I don't know where inside they grip the wire. 

      -Use a narrower clips.

• Difficulty to zero the newton-meter used when used horizontally.

      -Use a force sensor and computer.

• Voltmeter reading fluctuates because of contact resistance.

      -Clean the wires with wire wool first.

As long as your answers are logic and you write it in full, you can get the marks. 

Study Tips for SPM / How I Study

SPM is a very important exam. Everyone wants to strive for an excellent result so that they can get discount when studying foundation in college, get scholarships or bursaries (I don't care if they still have this) or just purely show-off?
Whatever the reasons are, SPM is still very important. So, I'm going to tell u guys some tips for the subjects that I sat SPM


The first ultimate tip is...
DO NOT leave the questions blank! The time for each paper is super long, so you don't have any excuses that you can't finish the paper. Just write anything that make sense (even though it doesn't make sense, you still have to write it). Who knows you're just lucky enough to obtain a few more marks. Right?

The second ultimate tip is...
Write as much as you can. This comes to hand in all subjects except Maths and Additional Maths. No matter how much you write, your mark will not be deducted. If you're lucky enough, maybe you can gain a few marks. 



1. Bahasa Malaysia/Melayu
For the komsas/ novel section, I depended on my tuition centre. My tutor will force us to read komsas in class instead of at home because you know, we won't read it at home. If your teacher attempt to make you read it in school, just do it. It's for your own good. Know the story line, and everything is good.

As for the essay, read a lot of news. The latest news, the better. Then, try to stuff everything you know into your essay. Good Malay is a must, but honestly peribahasa is not that important. The part that you have the general knowledge is more significant. 

For the tatabahasa, erm...I'll just skip this part. HAHAH 



2. BI
Read your freaking novel no matter how boring it is. You still have to deal with it. Just remember the story line then ok, you're done.
For essay, read a lot of storybooks, I guess... 

Oh well, language subjects are really hard to give tips, y'know... 


3. Maths / Additional Maths
Do a lot of exercise. Get use to how the questions ask and where do you apply which formula. Additional Maths is the only subject that I think the time is crucial. So, if you can't do the first questions, skip it. Just do whatever you know first and come back to the questions you don't know. Don't waste to much time when you know it is useless to do so.


4. Sejarah
Use your textbooks wisely. Love your textbooks because it is important compared to reference books. Textbooks have all the things you need to memorize. Don't freaking use the shitty reference books that give extra information and make you confused and waste time and angry and stressed and...
So, how many times exactly do you have to read your textbooks before SPM? I would say two times...For the first time, read it in detail. As for the second time, just scan through la. You don't have much time to spend for this shit.


5. P. Moral
This subject is extremely annoying. I was so frustrated of this particular subjects. Why? Because they keep on changing the format!!! If they want to change format just let them be because there's an ultimate tips for Moral which is...

Watak+definisi+huraian+huraian+...+contoh+contoh+...

Yes, that's right! Just write as many huraian and contoh as you can. Squeeze your brain juice and think. 


6. Physics
I hate this the most out of the three sciences. Let's get back to the point...
If I'm not wrong, a lot of definitions will be asked in the paper. So, just list out every definition in a piece of paper or small booklets or whatever you like, then start memorize it. Nevertheless, do past paper and exercises to get used of the pattern of the questions.


7. Chemistry
Same thing again, do a lot of past paper. And, DON'T FORGET to balance your freaking equation. Basically, chemistry is to test your understanding, so make sure you read your notes or reference book and understand the details fully. Make your own notes if you can since there's alot of colour solution and precipitated which is hard to memorize.


8. Biology
Once again, do your past paper!
Biology, like Sejarah is pure memorize (for SPM). I know it is hard to memorize all those terms. So, you'll have to make your own mindmap. Either you scribble it or draw it nicely on a piece of paper. Diagrams and pictures are always useful to make you remember things better. 


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Those are the subjects that I sat SPM. So, how exactly do I study for it?

To be honest, I am a very lazy student, and I tend to do everything in last minute. But, I still manage to get 9As for my SPM.

SPM English is still considered okay, I bet most people have no problem with it. 

However, SPM BM is really a pain in ass. I really hate studying BM, but I still gotta do this shit. I swear I depended on my tuition centre all the way because I don't study BM at home. 

Maths is easy, so I don't give much attention to it.

Add maths is two times harder than Maths. I went for extra class for this subjects, so I manage to do at least one paper every week. 

I think I only read the Sejarah textbooks three times during my Form 5 year. One before the semester exam, and two times before SPM. Even if I read it every single day, I'll still going to forget it. So why not last minutes?

There's a short break before my P.Moral paper. So I just take the time to swallow all the definisi. 

I think I'm just lucky for Physics. Paper 1 was always hard for me. I attend tuition class for this subject too.

Chemistry is my favourite out of the 3 sciences. My Chemistry teacher was very lenient and she made the subject very interesting so I can remember and memorize very well.

I attended a Biology seminar few days before the real paper. That seminar really made me have hope in myself. They didn't give tips but instead they give a lot of notes in diagram form. I use the remaining days to swallow all the diagrams. 


If you think you're more hardworking than me, then I'm sure you can scored very well in SPM.