OBSERVING REDOX REACTIONS
I. Aim
Observe the spontaneous redox reaction and know its characteristics
Observe the spontaneous redox reaction and know its characteristics
II. Theoretical Basis
A.
Redox
Redox is a chemical reaction in which there is transfer of electrons from one reactant to another reactant (Stoker, 2012).
1). Corrosion Corrosion is a spontaneous redox reaction that results in rust on iron, silver sulfide from silver, and copper (copper carbonate) copper.
2) Electrolysis Electrolysis is the process by which electrical energy is used to encourage a non-spontaneous redox reaction to occur.
3) Galvanic Thermodynamics The voltage measured in a galvanic cell can be broken down into the electrode potential of the anode (the site of oxidation) and the cathode (the reduction site). This voltage can be attributed to the change in Gibbs free energy and the equilibrium constant of the redox process.
B.Spontan and Non-Spontaneous
Spontaneous redox reaction is a continuous redox reaction and accompanied by the release of heat energy characterized by temperature changes (Salirawati, 2008). Non-spontaneous redox reaction occurs when the price of E ° cells is negative. A chemical reaction (including a redox reaction) that is not spontaneous does not occur (Salirawati, 2008).
Factors that cause redox reactions
(Oxtoby, 2004)
A.Energy ionization The more eletrophositive the element will be the easier to release the electrons, or the ionization energy is lowered so that the oxidation potential decreases while the reduction potential will rise.
B.Afectivity of electron Semakain eletronegatif elements then the electron affinity will also increase so that the reduction potential also rises.
C.Energy ionization The potential of the reduction standard is measured in atomic state so that atomization energy also determines the potential magnitude of the reduction standard.
D. Solvent energy If the redox process is carried out in the liquid phase, solvency energy also affects the amount of standard reduction potential.
E. Covalent bonding energy Large covalent binding forces support the reaction spontaneity; The potential of the reduction standard is proportional to the covalent bond energy.
F.Oxigen In accordance with the principle of redox reaction where there is also addition and reduction of oxygen in the compound.
Redox application in agricultural technology
Application of redox reactions in the field of agricultural technology is in the respiration of plants one of them in the process of photosynthesis because in the process of photosynthesis plants can produce oxygen and sugar. Sugar or glucose is a substance-making substance for plants so in this process the plant (Ebbing, 2010).
III. Tools and materials
Redox is a chemical reaction in which there is transfer of electrons from one reactant to another reactant (Stoker, 2012).
1). Corrosion Corrosion is a spontaneous redox reaction that results in rust on iron, silver sulfide from silver, and copper (copper carbonate) copper.
2) Electrolysis Electrolysis is the process by which electrical energy is used to encourage a non-spontaneous redox reaction to occur.
3) Galvanic Thermodynamics The voltage measured in a galvanic cell can be broken down into the electrode potential of the anode (the site of oxidation) and the cathode (the reduction site). This voltage can be attributed to the change in Gibbs free energy and the equilibrium constant of the redox process.
B.Spontan and Non-Spontaneous
Spontaneous redox reaction is a continuous redox reaction and accompanied by the release of heat energy characterized by temperature changes (Salirawati, 2008). Non-spontaneous redox reaction occurs when the price of E ° cells is negative. A chemical reaction (including a redox reaction) that is not spontaneous does not occur (Salirawati, 2008).
Factors that cause redox reactions
(Oxtoby, 2004)
A.Energy ionization The more eletrophositive the element will be the easier to release the electrons, or the ionization energy is lowered so that the oxidation potential decreases while the reduction potential will rise.
B.Afectivity of electron Semakain eletronegatif elements then the electron affinity will also increase so that the reduction potential also rises.
C.Energy ionization The potential of the reduction standard is measured in atomic state so that atomization energy also determines the potential magnitude of the reduction standard.
D. Solvent energy If the redox process is carried out in the liquid phase, solvency energy also affects the amount of standard reduction potential.
E. Covalent bonding energy Large covalent binding forces support the reaction spontaneity; The potential of the reduction standard is proportional to the covalent bond energy.
F.Oxigen In accordance with the principle of redox reaction where there is also addition and reduction of oxygen in the compound.
Redox application in agricultural technology
Application of redox reactions in the field of agricultural technology is in the respiration of plants one of them in the process of photosynthesis because in the process of photosynthesis plants can produce oxygen and sugar. Sugar or glucose is a substance-making substance for plants so in this process the plant (Ebbing, 2010).
III. Tools and materials
Tool :
Ø Beaker
Ø Measuring
cup
Ø Droppipette
Ø Sandpaper
Ø Cut out
cans
Material
:
Ø Cu and Zn
metals are each shaped
Ø 0.1 M
ZnSO4 solution
Ø HCl 0.1 M
Ø CuSO4
III. Ways of working
1.
As many as 4 pieces of 100ml glasses of glass are
provided and each glass is marked with the letters A, B, C and D.
2.
A total of 50 ml of CuSO4 0.1 M and 50 ml of ZnSO4
0.1 M each were inputted into glass A and glass B.
3.
A total of 50 ml of Hcl 0.1 M were fed into
glasses C and D.
Observe the color of the initial solution.
Observe the color of the initial solution.
4.
The slated Zn metal plate is inserted in glass A
and glass C respectively.
5.
Observe the changes.
6.
The slabs of Cu metal that have been sanded each
are inserted into glass B and Glass D.
7.
Observe the changes.
IV. Observation Result
NO METAL CHEMICAL METALS
A B C D
1 Type of CuSO4 solution ZnSO4 HCl HCl
2 Type of metal in the dip Zn Cu Zn Cu
3 Early colors of Blue Bening Bening Bening
4 Colors of the final solution of Bening Bening Bening Blue
5 Changes that occur rusting Keep Fixed gas Stay
Discussion
In this lab, experiments were made to make ZnSO4 solution
By reacting Zn metal with CuSO4 solution
. In this practicum Zn plate is obtained from a used battery, while CuSO4 solution obtained from the previous practice is making CuSO4 solution
Through the electrolysis process. Experiment of making ZnSO4
This can be done based on the theory that has been described in the introduction. When the zinc plate is inserted into a copper sulfate solution, the copper ions in CuSO4 solution are reduced to Cu metal while the zinc oxidizes to Zn2 + ions or in other words, the Zn metal will dissolve. This process is gradual but fast enough, it only takes a few minutes. After the zinc plate is inserted in CuSO4 solution, there is a direct reaction which produces heat which indicates the reaction takes place exothermic, smoky, smells of pungent, and many bubbles in solution that look like a boiling solution. After some time it looks like the zinc will be coated by a brown red copper. And the blue color of CuSO4 solution
Gradually faded. Until finally the Zn plates run out, the brown Cu metal precipitates, and the ZnSO4 solution
The unshaven is perfectly formed. This reaction takes place spontaneously. Each zinc atom loses two electrons to become a zinc ion and each copper ion gets two electrons into a copper atom. The electron is given directly from the zinc atoms to the copper ions. So in the equation the reaction can be written as follows: Zn (s) + Cu2 + (aq) → Zn2 + (aq) + Cu (s)
V. Question
Which glass reaction is spontaneously write down the equation of the reaction
Spontaneous reaction of glass A and Glass C with solution of CuSO4 and glass C with HCl solution, in insert metal
Glasses A and C → react spontaneously
K: Cu2 + + 2e- → Cu Eo = + 0.34 volts
A: Zn → Zn2 + + 2e- Eo = - 0.76 volts
R. Redox: Cu2 + + Zn → Cu + Zn2 + Eo cells = 1.10 volts (spontaneously)
By reacting Zn metal with CuSO4 solution
. In this practicum Zn plate is obtained from a used battery, while CuSO4 solution obtained from the previous practice is making CuSO4 solution
Through the electrolysis process. Experiment of making ZnSO4
This can be done based on the theory that has been described in the introduction. When the zinc plate is inserted into a copper sulfate solution, the copper ions in CuSO4 solution are reduced to Cu metal while the zinc oxidizes to Zn2 + ions or in other words, the Zn metal will dissolve. This process is gradual but fast enough, it only takes a few minutes. After the zinc plate is inserted in CuSO4 solution, there is a direct reaction which produces heat which indicates the reaction takes place exothermic, smoky, smells of pungent, and many bubbles in solution that look like a boiling solution. After some time it looks like the zinc will be coated by a brown red copper. And the blue color of CuSO4 solution
Gradually faded. Until finally the Zn plates run out, the brown Cu metal precipitates, and the ZnSO4 solution
The unshaven is perfectly formed. This reaction takes place spontaneously. Each zinc atom loses two electrons to become a zinc ion and each copper ion gets two electrons into a copper atom. The electron is given directly from the zinc atoms to the copper ions. So in the equation the reaction can be written as follows: Zn (s) + Cu2 + (aq) → Zn2 + (aq) + Cu (s)
V. Question
Which glass reaction is spontaneously write down the equation of the reaction
Spontaneous reaction of glass A and Glass C with solution of CuSO4 and glass C with HCl solution, in insert metal
Glasses A and C → react spontaneously
K: Cu2 + + 2e- → Cu Eo = + 0.34 volts
A: Zn → Zn2 + + 2e- Eo = - 0.76 volts
R. Redox: Cu2 + + Zn → Cu + Zn2 + Eo cells = 1.10 volts (spontaneously)
Mention the characteristics of the spontaneous
redox reaction of the experiments performed.
·
Discoloration
·
Shaped gas
·
There are deposits
·
Eo cells positive
VI. Conclusion
Zn
metals undergo spontaneous redox reactions when inputted to CuSO4 and HCl
solutions
In the solution of ZnSO4 and HCl, the input of Cu metal does not undergo a redox reaction
In the solution of ZnSO4 and HCl, the input of Cu metal does not undergo a redox reaction
VII. Bibliography
can you explain about redoks reaction
BalasHapusRedox is a term that describes the change in oxidation state (oxidation state) of atoms in a chemical reaction.
HapusThis can be a simple redox process such as carbon oxidation that produces carbon dioxide, or carbon reduction by hydrogen to produce methane (CH4), or it can be a complex process such as the oxidation of sugar in the human body through a series of complicated electron transfers.
The term redox comes from two concepts, namely reduction and oxidation. It can be easily explained as follows:
Oxidation describes the release of electrons by a molecule, atom, or ion
Reduction describes the addition of electrons by a molecule, atom, or ion.
Although quite appropriate for use in various purposes, the above explanation is not exactly true. Oxidation and reduction precisely refer to changes in oxidation numbers because actual electron transfer will not always occur. So that oxidation is better defined as an increase in oxidation number, and reduction as a decrease in oxidation number. In practice, electron transfer will always change the oxidation number, but there are many reactions that are classified as "redox" even though there is no electron transfer in the reaction (eg involving covalent bonds).
Why we need to make a report after doing experiment ?
BalasHapusUsually after experimenting, we have to write a report about the experiments we have done. It is important to know what we have done and the results we get. The experimental report also meruakan one form of scientific communication indirectly with others.
HapusPlease explain redox reactions based on changes in oxidation numbers
BalasHapusThe concept of universal redox reactions to the reactions involving covalent compounds which are difficult redox .Reaksi explained by the concept of oxygen and electrons can be easily explained using the concept of oxidation.
Hapus