Corrosive"
Teacher : Good Afternoon Class
Students : Good Afternoon ma'am
Teacher : Well, Can you guess what the stuff I bring?
Students : No ma'am, We don't know
Teacher : It's call hydrocloric acid solution
Students : Ohh
Teacher : Does anybody know the characteristic about hydrocloric acid solution from the way you see it?
Amel : I know
Teacher : Yes please
Amel : It has clear color ma'am
Teacher : exactly, anybody else? yes please
Rika : hydrocloric acid solution is a strong acid ma'am
Teacher : That's right!
Oni : But ma'am, why hydrocloric acid solution it strong acid?
Teacher : Nice question! well that's because hydrocloric acid solution has mixed by 2 elements, which is hydrogen and cl have strong ion bond, so that's can make a strong power to create a strong bond. Here do you see this symbol?
Students : Yes, we are
Teacher : So anybody can analyze the meaning of this symbol?
Rika : Can I ma'am?
Teacher : Yes please
Rika : That's symbol has mean corrosive. the chemical material can destructive life tissue, and then can make irritation on the skin. we can feel itchy because of that and our skin will peel
Teacher : Yeah! that's exactly what you say. Now we will to prove that hydrocloric acid solution is corrosive. Do you guys bring what I command last week?
Student : Yes ma'am
Teacher : Bring it here please
Amel : Here you are
Teacher : Well, you guys can take a look what I will doing, so what will happen if I trying to drop the solution on the steroform?
Oni : Woahh awasome... the steroform is melting
Amel : It's Amazing
Teacher : So you see it? it's melting right? this experiment has prove one of the hydrocloric acid solution characteristic, so what is the conclusion about this experiment?
Oni : So the conclusion is hydrocloric acid solution is a strong acid, and it can separate in the water, hydrocloric acid solution is made by covalent bond between H and Cl . And it can make the steroform melt, uhh I mean like it has corrosive characteristic
Teacher : Yeah that's right. that is the conclusion about hydrocloric acid solution, okay I think it's enough, I hope you learn more about this lesson, see you next week.
Give example of corrosive hydrochloric acid solution?
BalasHapusHCl (Chloride Acid), H2SO4 (Sulfuric Acid), CH3COOH (Acetic Acid / Vinegar), orange juice
Hapuswhy hydrocloric acid solution is a strong acid?
BalasHapusHydrochloric acid is a strong acid, and is made up of hydrogen and chlorine atoms. Hydrogen and chlorine atoms in covalent bonds, which means hydrogen will share with chlorine atoms. This covalent bond is present until air is added to the HCl. Once added to the air, HCl will separate into hydrogen ions (which are positive and will pass on air molecules) and chloride ions (negative ones).
HapusCan you give examples of experiments other than drop the solution on the steroform?
BalasHapusI did not find any other experimental example
Hapuswhat the chemical reaction in corrosion?
BalasHapusOne example of corrosion that occurs in iron, or commonly referred to as rust. The corrosive iron forms rust with the formula Fe2O3.XH2O. In the process of observation, iron (Fe) acts as a preduction and Oxygen (O2) dissolved in air acts as an oxidizer. The corrosion-forming reaction equation:
HapusAnode: Fe2 + + 2e- → Fe
Cathode: 2H2O → O2 + 4H + + 4e-
I would like to ask whether it is harmless to bring harmful substances such as strong acids into a class without complete equipment?
BalasHapusVery dangerous but who did not introduce the teacher is not a student and they just see what happens
HapusIs a 5-centimation approach in this dialog?
BalasHapusConstructivism approach: Between existing knowledge must be related to the experience in students.
HapusActive students ask, answer
The flow of student and teacher interaction
Students so know if it matters
Excellent class atmosphere on learning
Mention examples of hydrochloric acid in everyday life?
BalasHapusHydrochloric acid is used in the metal industry to remove rust or iron oxide crust from iron or steel.
HapusAs a raw material for the manufacture of vinyl chloride, which is a monomer for the manufacture of polyvinyl chloride or PVC plastic.
HCl is the raw material of iron (III) chloride (FeCl3) and polyalumunium chloride (PAC), which are chemicals used as raw material for coagulant and flocculant. Coagulants and flocculants are used in air treatment.
Hydrochloric acid is used for air testing purposes, before being discharged to.
HCl is also used in the regeneration process of cation exchange resins (cation exchange resins).
In the laboratory, hydrochloric acid is commonly used for the titration of base degradation in a solution.
Hydrochloric acid is also useful for making porcelain cleaning fluid.
HCl is used in the production of gelatin and additives in foods.
On an industrial scale, HCl is also used in skin processing.
The mixture of hydrochloric acid and nitric acid (HNO3) or commonly referred to as aqua regia, is a mixture for dissolving gold.
Other uses of hydrochloric acid are in the production process of batteries, fireworks and camera flash lights.