DIALOGE OF TEACHER AND STUDENT
ABOUT CHEMISTRY LESSON.
Time Chemical Class
Teacher : Assalamualaikum my student
Students : Waalaikumsalam miss
Teacher : is ready to study chemistry today? Is today's material already learned at home?
Students : already a book
Teacher : well today we will discuss about redox reactions. If you have studied at home. What is a redox reaction?
Student : I am miss, redox reaction comes from the word reduction and oxidation. Reduction is a chemical reaction involving electron capture, release of O2 and a decrease in oxidation number. While oxidation is a chemical reaction involving the release of electrons, the release of hydrogen, the binding of oxygen and the raising of oxidation numbers.
Teacher : very well described by your friend, in redox reaction there are three concepts, that is related to oxygen, with electrons and with biloks.
Student : miss, I want to ask how the redox example relates to electrons?
Teacher : okay, in relation to the reduction electrons happen to capture or receive electrons and on the oxidation of electrons.
For example Mg2+ + 2e- --> Mg
Example above what is the reduction of oxidation?
Student : miss reduction, because Mg receives electrons.
Teacher : good, for biloks we have to know the rules of biloks first.
1. Free element, biloks = 0
2. The oxygen atom in the oxidation compound = -2
3. Atoms of hydrogen biloks = 1
4. Atoms of ions / compounds of oxidized ions = groups
5. The element of group IA, IIA, IIIA biloks = group
Teacher : who can determine the oxidation state of MnO2 ?
Student : I'm a miss,
Teacher : okay do it in front
Student : MnO2
2 x (-2) + 4 = 0
So the answer = +4
Teacher : good job. So the oxidation reaction takes place simultaneously with the reduction reaction and called the redox reaction. Substances undergoing oxidation reactions are called reducing agents. While substances that undergo a reduction reaction called oxidizer (peoksidasi). Do you understand?
Students : understand the book
Teacher : well enough for our lesson today, see you next week.
Wassalamu alaikum warahmatullahi wabarakatuh
Student: waalaikumsalam miss.
Teacher : Assalamualaikum my student
Students : Waalaikumsalam miss
Teacher : is ready to study chemistry today? Is today's material already learned at home?
Students : already a book
Teacher : well today we will discuss about redox reactions. If you have studied at home. What is a redox reaction?
Student : I am miss, redox reaction comes from the word reduction and oxidation. Reduction is a chemical reaction involving electron capture, release of O2 and a decrease in oxidation number. While oxidation is a chemical reaction involving the release of electrons, the release of hydrogen, the binding of oxygen and the raising of oxidation numbers.
Teacher : very well described by your friend, in redox reaction there are three concepts, that is related to oxygen, with electrons and with biloks.
Student : miss, I want to ask how the redox example relates to electrons?
Teacher : okay, in relation to the reduction electrons happen to capture or receive electrons and on the oxidation of electrons.
For example Mg2+ + 2e- --> Mg
Example above what is the reduction of oxidation?
Student : miss reduction, because Mg receives electrons.
Teacher : good, for biloks we have to know the rules of biloks first.
1. Free element, biloks = 0
2. The oxygen atom in the oxidation compound = -2
3. Atoms of hydrogen biloks = 1
4. Atoms of ions / compounds of oxidized ions = groups
5. The element of group IA, IIA, IIIA biloks = group
Teacher : who can determine the oxidation state of MnO2 ?
Student : I'm a miss,
Teacher : okay do it in front
Student : MnO2
2 x (-2) + 4 = 0
So the answer = +4
Teacher : good job. So the oxidation reaction takes place simultaneously with the reduction reaction and called the redox reaction. Substances undergoing oxidation reactions are called reducing agents. While substances that undergo a reduction reaction called oxidizer (peoksidasi). Do you understand?
Students : understand the book
Teacher : well enough for our lesson today, see you next week.
Wassalamu alaikum warahmatullahi wabarakatuh
Student: waalaikumsalam miss.
Explain the stages of determining the oxidation number?
BalasHapusHow to determine the oxidation number of an element in the ion or its compound follows the following rules:
HapusA. The oxidation number of the free element (atom or element molecule) is 0 (zero).
B. The oxidation number of monoatomic and polyatom ions is equal to the ion charge.
C. The class IA elemental oxidation number is +1 and the class IIA element is +2.
D. The oxidation number of the VIA element of the binary compound is -2 and the VIIA group element in the binary compound is -1.
E. The oxidation number of element H on its compound is +1. For example, the oxidation number of element H on H2O, HCl, H2S, and NH3 is +1. The oxidation number of element H in the hydride compound is -1. For example, the oxidation number of element H in NaH, CaH2, and AlH3 is -1.
F. The oxidation number of element O on its compound is -2, except in the binary compound with F, the oxidation number of the element O is +2. The oxidation number of element O on peroxide compounds, such as H2O2 and BaO2 is -1.
G. The number of oxidation states for all the elemental atoms in a molecule or compound is 0. The sum of oxidation numbers for atoms or poliomy ion-forming elements is equal to their polyatomic ion charge.
How an element is said to be oxidizing???
BalasHapusA substance is said to be oxidizing when it can cause another substance to oxidize while it itself undergoes reduction
HapusWhat methods are used to determine the oxidiser?
BalasHapusTo determine the reducing agents and oxidizers in a reaction, the steps are:
Hapus1. Under the element written oxidation number. Write the known oxidation number first. If not known assisted with calculations on it.
2. Determine the elements that have changed the oxidation number. From the above problem Mn experiences a change of oxidation from +4 to +2 (decrease in oxidation). Mn on MnO2 is reduced, so MnO2 is an oxidizing agent. Cl changes the oxidation state also from -1 to o (increase in oxidation). Cl on HCl is oxidized, so HCl is a reducing agent.