Write 5 Examples Of Decomposition Reaction
Answers
Answer:
Explanation:
Hydrogen peroxide is a widely used disinfectant for minor cuts and scrapes. You may have a bottle of hydrogen peroxide like the one pictured here in your medicine cabinet at home. Did you ever notice that hydrogen peroxide is always kept in a dark brown bottle like this one? Do you know why? The reason is that hydrogen peroxide needs to be protected from light. If it isn’t, it will gradually break down to water and oxygen. This is a decomposition reaction.
What Is A Decomposition Reaction?
A decomposition reaction occurs when one reactant breaks down into two or more products. It can be represented by the general equation:
AB → A + B
In this equation, AB represents the reactant that begins the reaction, and A and B represent the products of the reaction. The arrow shows the direction in which the reaction occurs.
Q: What is the chemical equation for the decomposition of hydrogen peroxide (H2O2) to water (H2O) and oxygen (O2)?
A: The equation for this decomposition reaction is:
2 H2O2 → 2 H2O + O2
Other Examples of Decomposition Reactions
Two more examples of decomposition reactions are described below.
Carbonic acid (H2CO3) is an ingredient in soft drinks. A decomposition reaction takes place when carbonic acid breaks down to produce water (H2O) and carbon dioxide (CO2). This occurs when you open a can of soft drink and some of the carbon dioxide fizzes out. The equation for this reaction is:
H2CO3 → H2O + CO2
Another decomposition reaction occurs when water (H2O) breaks down to produce hydrogen (H2) and oxygen (O2) gases (see Figure below). This happens when an electric current passes through the water, as illustrated below. The equation for this reaction is:
2 H2O → 2 H2 + O2
Q: What ratio of hydrogen molecules (H2) to oxygen molecules (O2) is produced in the decomposition of water?
A: Two hydrogen molecules per oxygen molecule are produced because water (H2O) has a ratio of two hydrogen atoms to one oxygen atom.
Summary
A decomposition reaction occurs when one reactant breaks down into two or more products. This can be represented by the general equation: AB → A + B.
Examples of decomposition reactions include the breakdown of hydrogen peroxide to water and oxygen, and the breakdown of water to hydrogen and oxygen.
Review
What is a decomposition reaction? What is the general equation for a decomposition reaction?
Describe the decomposition of hydrogen peroxide, and write a balanced chemical equation for this reaction.
Which of the following chemical equations represents a decomposition reaction?
H2SO3 → H2O + SO2
2Na + Cl2 → 2NaCl
2K + 2H2O → 2KOH + H2
NaCl + AgF → NaF + AgCl
2. Carbonic Acid (H2CO3) is an ingredient in soft drinks. A decomposition reaction takes place when carbonic acid breaks down to produce water(H2O) and carbon dioxide (CO2). This occurs when you open a can of soft drink and some of the carbon dioxide fizzes out. The equation for this reaction is:
H2CO3 → H2O + CO2
3.Another decomposition reaction occurs when water (H2O) breaks down to produce hydrogen (H2) and oxygen (O2) gases . This happens when an electric current passes through the water, as illustrated below. The equation for this reaction is:
2 H2O → 2 H2 + O2
✍️ Ankush Kumar Jha
31.7k views · View 31 Upvoters · View Sharers
Related QuestionsMore Answers Below
What are some examples of decomposition reactions?
What is decomposition reaction and what are some examples?
What are some examples of double replacement reaction in everyday life?
What are some examples of everyday synthesis and decomposition reactions?
What are some examples of double replacement reactions in real life?
Anuradha Das
Anuradha Das, Student of Physics and Chemistry.
Answered May 13, 2018 · Author has 238 answers and 319.4k answer views
Originally Answered: What are some examples of decomposition reactions?
EXAMPLES OF DECOMPOSITION REACTIONS :
EXAMPLE 1 : When Calcium carbonate is heated, it decomposes to give calcium oxide and carbon dioxide gas.
Reaction : CaCO3 →CaO + CO2
EXAMPLE 2 : When potassium chlorate is heated, it decomposes into potassium chloride and oxygen.
Reaction : 2KClO3 → 2KCl + 3O2
EXAMPLE 3 : Silver chloride decomposes into silver and chlorine in the presence of sunlight.
Reaction : 2AgCl →2Ag + Cl2
EXAMPLE 4 : On heating, lead nitrate decomposes into lead monoxide, nitrogen dioxide and oxygen.
Reaction : 2Pb(NO3)2 → 2PbO + 4NO2 + O2
Ex 1. Electrolytic decomposition of molten sodium chloride: On passing electric current through molten sodium chloride, it decomposes to give sodium metal and chlorine gas :
Ex 2. Electrolytic decomposition of molten alumina (aluminium oxide): On passing electric current through molten alumina, it decomposes to give aluminium metal and oxygen gas :
In this reaction, on passing electric current, a single substance i.e. alumina decomposes to give two simpler substances, aluminium metal and oxygen gas, thus it is an example of electrolytic decomposition reaction.
Photo-decomposition reactions (or photolysis):
The decomposition reactions which take place by absorption of light are called the photo-decomposition reactions or photolysis.
Ex 3. Photo-decomposition of silver chloride or Photolysis of silver chloride
Experiment: Take a pinch of silver chloride on a watch glass and keep it in sunlight for some time.
Decomposition of silver chloride in the presence of light
It is observed that white silver chloride turns gray due to formation of silver metal.
Ex 4. Photolysis of hydrogen iodide: Hydrogen iodide decomposes in the presence of ultraviolet light into hydrogen and iodine :
Ex 5. Photolysis of hydrogen peroxide: In presence of light, hydrogen peroxide decomposes into water and oxygen.
Since hydrogen peroxide decomposes in the presence of light, that is why, hydrogen peroxide is kept in coloured bottles so as to cut off light.
Decomposition reactions are called the opposite of combination reactions
In a decomposition reaction, one substance breaks up into two or more chemical substances, while in a combination reaction two or more substances combine to form one single substance. So these two reactions are called opposite of each other.