Annex A - Group Research Proposal

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Group Project Proposal (Science)



Names: Roy Tay, Haw Jin Yu, Noel Lim, Siddhartha Jaruhar

Class: S2-01______

Group Reference: F


1.    Indicate the type of research that you are adopting:


[     ] Test a hypothesis: Hypothesis-driven research

    e.g. Investigation of the anti-bacteria effect of chrysanthemum


[     ] Measure a value: Experimental research (I)

e.g. Determination of the mass of Jupiter using planetary photography


[ X ] Measure a function or relationship: Experimental research (II)

e.g. Investigation of the effect of temperature on the growth of crystals


[     ] Construct a model: Theoretical sciences and applied mathematics

e.g. Modeling of the cooling curve of naphthalene 


[     ] Observational and exploratory research

    e.g. Investigation of the soil quality in School of Science and Technology, Singapore  


[     ] Improve a product or process: Industrial and applied research

    e.g. Development of a SMART and GREEN energy system for households  



2.    Write a research proposal of your interested topic in the following format:


Title: Investigation on the effect of amount of coke and salt content on the amount of voltage produced. 


A.    Question being addressed

We wanted to find out whether the amount of coke and salt content affects the voltage produced in our home-made battery. 


Background research 

Part 1 (Why coke produces a voltage?):


The copper holds onto its atoms more strongly than zinc does. The zinc strip has more negative charges than the copper strip, and the electrons flow from the zinc to the copper. 

When the forces are eventually balanced, the copper strip ends up with more electrons than the zinc strip. The zinc strip now has fewer electrons, and it cannot attract the zinc ions back to the strip.


If our battery just had water in it, not much more would happen. But our Coca-Cola battery has water plus phosphoric acid. An acid is something that has an easily detached hydrogen ion. Hydrogen ions are positive, and the remaining part of the acid becomes negative when it loses the hydrogen ion. In our battery, the remaining part is the phosphate ion. 


So what happens when all of those positively charged zinc ions bump into those negatively charged phosphate ions? The phosphate ion is more strongly attracted to the zinc ion than to the hydrogen ion. The positively charged hydrogen ion is attracted to the copper strip, because the copper strip has the extra electrons, and is thus negative. 


The hydrogen ions attract the electrons from the copper, and become neutral hydrogen atoms. These join up in pairs to become hydrogen molecules, and form bubbles on the copper strip. Eventually the bubbles become big enough to float up to the surface and leave the system entirely.

Now the copper strip no longer has the extra electrons. It attracts more from the zinc strip through the connecting wire, as it did when we first connected the wire. The copper ions next to the copper strip are not as attracted to the strip as they were before. The hydrogen ions keep taking the electrons that attracted the copper ions. So those ions are free to move through the liquid. 


At the zinc strip, zinc ions are being removed, leaving extra electrons. Some of those electrons travel through the wire to the copper strip. But some of them encounter the copper ions that happen to bump into the zinc strip. Those ions grab the electrons, and become copper atoms. We can see those atoms build up on the zinc strip. They look like a black film, because the oxygen in the water combines with the copper to form black copper oxide. Eventually, all of the zinc is eaten up, and the copper and copper oxide falls into a pile beneath where the zinc strip used to be. The battery is now dead, and no more electrons flow through the wire. If there was not a lot of acid in the water, it may be the first thing to be used up, and the battery may die while there is still some zinc left on the zinc strip. (FIELD, 2015)


Part 2 (Why salt decreases the voltage produced?):


Dropping salt in soda causes the salt to dissolve and subsequently reduce the availability of the soda's solvent to dissolve the carbon dioxide, which is due to the increase in solutes causing a change in the balance of the soda's chemistry, also causing the soda to release some of its carbon dioxide. The salt falling into the soda allows for the formation of nucleation sites for carbon dioxide bubbles. These bubbles transition to the surface and cause the bubbling effect you notice after pouring salt into soda. The salt dissolving into the soda causes a change in the pH balance of the solution. In return, the pH shift causes a decrease in the solubility of the carbon dioxide, thus releasing CO2 gas, or the bubbles you see when salt is combined with soda. As the battery heavily relies on the acid in the coke for it to work, the pH shift caused by the salt will cause less acid to produce voltage. This in turn leads to lower readings on the voltmeter. (KILHEFNER, 2015)



The independent variable is amount of coke and salt content. 

The dependent variable is the voltage produced.

The constants are:

(a)  The materials used to conduct electricity

(b)  The material of the cup

(c)  The type of coke

(d)  The voltmeter

(e)  The temperature of the surroundings

(f)  The temperature of the coke


B.    Hypotheses


The hypothesis is: The greater the amount of coke, and the lesser the amount of salt added to the coke, the more the voltage is produced. 


C.    Description in detail of method or procedures (The following are important and key items that should be included when formulating ANY AND ALL research plans.)


Equipment list: 

  1. Voltmeter (1 Voltmeter)
  2. Cup (1 Cup)
  3. Coke (4 1.5L Bottles)
  4. Zinc* strip (1 Strip)
  5. Copper strip (1 Strip)
  6. Crocodile clip wires (2 Wires)
  7. Measuring cylinder (1 Cylinder)
  8. Salt (1 Cup)

*Can be replaced with aluminium

Procedures: Detail all procedures and experimental design to be used for data collection
Testing how the amount of coke affects the voltage produced
  1. Start with an empty cup
  2. Pour 100 ml of coke into the cup. 
  3. Attach the aluminuim strip on one side, dipping it into the coke
  4. Attach the copper strip on the other side, dipping it into the coke as well. 
  5. Clip the aluminium and copper strips to the crocodile clip wires. 
  6. Clip the other end of the crocodile clip wires to the voltmeter. 
  7. Read the reading on the voltmeter. 
  8. Repeat steps 1 to 7, 2 more times, but using 200ml, and 300ml of coke respectively. 

Testing how the amount of salt affects the voltage produced
  1. Start with an empty cup
  2. Pour 100 ml of coke into the cup. 
  3. Attach the aluminium strip on one side, dipping it into the coke
  4. Attach the copper strip on the other side, dipping it into the coke as well. 
  5. Clip the aluminium and copper strips to the crocodile clip wires. 
  6. Clip the other end of the crocodile clip wires to the voltmeter. 
  7. Read the reading on the voltmeter. 
  8. Add 5 teaspoons of salt into the coke
  9. Read the reading on the voltmeter. 
  10. Repeat steps 8 and 9 2 more times. 
  11. Repeat steps 1 to 10 2 more times, but using 200 ml, and 300 ml of coke respectively.

Risk and Safety: Identify any potential risks and safety precautions to be taken.
  1. As this experiment involves electricity,very slight electrocution is possible so use a dry glove when handling wires. 
  2. As we might need to use scissors to cut the zinc and copper strips, handle scissors carefully. 
  3. As the copper or zinc strip might be sharp, use caution when cutting them. 
  4. This experiment involves acids although it is very mild, over concentration is possible. Use gloves when handling coke. 
  5. As this experiment requires handling of liquids, spillage is possible. Clean up any spillage immediately. 

Data Analysis: Describe the procedures you will use to analyse the data/results that answer research questions or hypotheses
  1. Tabulate the data of the voltage. 
  2. Plot a graph of the voltage against the amount of salt added to the coke. 
  3. From the graph, we can find out how salt affects the voltage produced. 

D. Bibliography: List at least five (5) major references (e.g. science journal articles, books, internet sites) from your literature review. If you plan to use vertebrate animals, one of these references must be an animal care reference. Choose the APA format and use it consistently to reference the literature used in the research plan. List your entries in alphabetical order.
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