Science Fair Research Paper

1 Zhan, Du Tara Zhan & Angela Du Ms. Wagner, Block F Science Fair Project 10.21.2016

Salt Bridge Over Electrified Waters Solutions come in three different types by pH. some are basic solutions, others are acidic solutions, while still others are neutral solutions. Although there are some different ways to change the pH of a solution, including heating, adding water, adding acid or basic substances, one can also change the pH by electrolysis using battery for it in this chemical science fair project. First, the main idea of this project is oxidation-reduction reaction. It is defined in chemistry as "the atomic of the elements have the corresponding changes before and after reactions". It means the electrons move from one atom to another, during oxidation atoms loss electrons, and during reduction atoms get electrons. According to Nelson, M. Rae in their chapter, "Oxidation-Reduction". When they put the dirty pennies into the solution, the copper oxide and copper will dissolve into the water, we know acids are important reducing agents and it leads to a reducing reaction, it is the reduction, and also like vinegar can form a blue-green solid in an oxidation reaction with copper. Because oxidation-reduction reactions can change the amount of ions, so the pH of solutions can change. A electrochemical reaction is any process either caused or accompanied by the passage of an electric current and involving in most cases the transfer of electrons between two substances—one a solid and the other a liquid. Dissociation

2 Zhan, Du is the separation ion of a molecule into smaller molecules, atoms, or ions, especially by a reversible process. A reversible process is a process whose system can go back to its original state, while eliminating the original process of all the influence on environment. Decomposition is the state or process of decay; Oxidation is the process or result of oxidation or oxidation; an electrolyte, which contains ions and can be decomposed by electrolysis liquid, or gel, such as a liquid or gel present in a battery. Secondly, pH is another main term in this project. The abbreviation pH is from the "Potential of Hydrogen", which means hydrogen power or hydrogen ion concentration. The pH of a solution is a measure of the total number of hydrogen ions divided by the amount of total material. In the solutions, the hydrogen ions produced by the self-ionization of water. In other words, the pH is also expressed as the concentration of the hydrogen ion (or positively charged hydrogen atom) of the solution, since the H3O+ ion is formed by the H + ion and the water molecule. The pH is measured from 0 to 14 on the scale. Therefore, the pH is a measure of the acidity or alkalinity of a solution based upon the dissociation of water. According to Nelson, M. Rae, "pH", like acids produce a hydrogen ion, bases produce a hydroxide ion, (H2O → H+ + OH-, meaning H+ and OH-ions can join to form H2O, a neutral substance), and the leftover substance is a salt. Also, HCl → H+ + Cl-, that the hydrochloric acid molecule dissociates into a hydrogen ion and a chloride ion. There is an important equation "NaOH → Na+ + OH-", which NaOH represents sodium hydroxide, Na+ represents sodium ion, and OH- represents hydroxide ion. Hydrogen atom which is an atom of the chemical element hydrogen; The oxygen atom is a chemical element with the symbol O and the atomic number 8; the acid is a chemical that neutralizes the base, dissolves some metal, and makes the litmus red; usually this is a corrosive

3 Zhan, Du and sour liquid; hydrogen ion, the nucleus of the hydrogen atom. With its accompanying electron separation. Hydroxide ion, which is a diatomic anion having the formula OH-. A cathode with a charged electrode through which the electrons enter the electrical device; a reduction rate, which is a premium, and is often refunded in cash or can be used in retroactive forms of credit for applying future premiums; anodes, positively charged electrodes, electrons passing through the anode, leave the device. Magnesium sulfate, having the formula MgSO4, which is an inorganic salt containing magnesium, sulfur and oxygen; a salt bridge, which is a connection between a charged acidic group and a basic group, Particularly in different parts of macromolecules such as proteins. MgSO4 consists of an oxygen and atom held together by a covalent bond, and carries a negative electric charge. Hydrochloric acid which is a colorless, highly pungent solution of hydrogen chloride in water. A base which is over 7 on the pH scale; Sodium hydroxide which is also known as lye and caustic soda, is an inorganic compound; pH scale which measures how acidic or basic a substance is. The pH scale ranges from 0 to 14. A pH of 7 is neutral and it is logarithmic. The pH less than 7 each integer value is higher than in the next ten times the value of the acid. For example, a solution of pH 4.0 acidic compared to pH 5.0 is 10 times more acidic. A solution of pH 3.0 acidic 1000 times higher than that in the solution pH is 6.0. For pH value is higher than 7, so each value lower than the next integer alkaline 10 times (another way called alkaline). For example, 10 times higher than alkaline pH 8.0, pH 9.0 more than 100 times the alkaline pH 7.0 (10 times as much as 10. Based on this research paper, we know if use sodium chloride instead of magnesium sulfate as an electrolyte will form Chlorine(Cl2) and Hydrogen(H2) gases. The ratio of the volume of hydrogen gas to the volume of oxygen gas formed in the electrolysis of water is 2:1,

4 Zhan, Du because through study the equations H2O → H2 (gas) + 1/2 O2 and 2 H2O → 2 H2 (gas) + O2, the volume of hydrogen gas is two times the volume of oxygen gas. The pH of the solution near the positive terminal (anode) of the battery will get higher as electrolysis proceeds. When chemical is oxidized, it is happened oxidation-reduction reaction. Similarly to Nelson, M. Rae's science fair projects, Tara Zhan and Angela Du will test the change in pH of two salt solutions that connect by a salt bridge, as a current of positive electrical and negative electrical charges is passed through them, and then we predict the salt solution that contains the Anode with two batteries, will have a higher pH than the solution that contains the Anode with one battery, also the salt solution that contains the Cathode with two batteries, will have a lower pH than the salt solution that contains the Cathode with one battery will happen. Be sure to include the independent variable which is the amount of electricity, the dependent variable which is the change of the pH of the solutions and other control variables such as temperature. All data will be recorded constantly in the lab notebook. Photos will be taken at each steps of the experiment to insure accountability and accuracy. Finally, after concluding the experiment, the results will be determined by comparing the pH higher or pH lower in the salt solutions that contain the cathode and anode.

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References: "pH." UXL Complete Life Science Resource. Ed. Julie Carnagie and Leonard C. Bruno. Detroit: UXL, 2009. Science in Context. Web. 24 Oct. 2016. Nelson, M. Rae. "Oxidation-Reduction." Experiment Central: Understanding Scientific. Principles Through Projects. Ed. Kristine Krapp. 2nd ed. Detroit: UXL, 2010. Science in Context. Web. 24 Oct. 2016. Nelson, M. Rae. "pH." Experiment Central: Understanding Scientific Principles Through Projects. Ed. Kristine Krapp. 2nd ed. Detroit: UXL, 2010. Science in Context. Web. 25 Oct. 2016.