Drawing up equations for the reactions of oxidation of substances with oxygen. Drawing up equations for the reactions of oxidation of substances with oxygen Combustion of phosphine in oxygen
Instruction
Copper (I) oxide - Cu2O. In nature, it can be found in the form of the mineral cuprite. It is also known by such names as cuprous oxide, copper hemioxide and dicopper oxide. Copper (I) oxide belongs to the group of oxides.
Chemical properties
Cu2O does not react with water. Copper (I) oxide dissociates to a minimum extent:Cu2O+H2O=2Cu(+)+2OH(-).
Cu2O can be brought into solution in the following ways:
- Oxidation:
Cu2O+6HNO3=2Cu(NO3)2+3H2O+2NO2;
2Cu2O+8HCl+O2=4CuCl2+4H2O.
- Reaction with concentrated hydrochloric acid:
Сu2O+4HCl=2H+H2O.
- Reaction between copper oxide (I) and concentrated alkali:
Cu2O+2OH(-)+H2O=2(-).
- Reaction with concentrated solutions of ammonium salts:
Cu2O+2NH4(+)=2(+).
- Reaction with concentrated ammonia hydrate:
Cu2O+4(NH3*H2O)=2OH+3H2O.
Cu2O in aqueous solution can carry out the following reactions:
- Oxidation with oxygen to Cu(OH)2:
2Cu2O+4H2O+O2=4Cu(OH)2.
- In the reaction with dilute hydrohalic acids (instead of HHal, you can put Cl, I, Br) copper halides are formed:
Cu2O+2HHal=2CuHal+H2O.
- The reaction with dilute sulfuric acid is disproportionation. That is, copper (I) oxide is both an oxidizing agent and a reducing agent at the same time:
Cu2O+H2SO4=CuSO4+Cu+H2O.
- Reduction reaction to Cu with sodium hydrosulfite, or any other typical reducing agents:
2Cu2O+2NaHSO3=4Cu+Na2SO4+H2SO4.
Reactions with hydrogen azide:
- Reaction at cooling 10-15оС:
Сu2O+5HN3=2Cu(N3)2+H2O+NH3+N2.
- Reaction at a temperature of 20-25оС:
Сu2O+2HN3=2CuN3+H2O.
Reactions when heated:
- Decomposition at 1800°C:
2Cu2O=4Cu+O2.
- Reaction with sulfur:
2Cu2O+3S=2Cu2S+SO2 (temperature above 600°C);
2Cu2O+Cu2S=6Cu+SO2 (temperature 1200-1300оС).
- In a stream of hydrogen, when heated, carbon monoxide reacts with:
Cu2O+H2=2Cu+H2O (temperature above 250°C);
Cu2O+CO=2Cu+CO2 (temperature 250-300оС);
3Cu2O+2Al=6Cu+2Al2O3 (temperature 1000оС)
Copper (II) oxide - CuO. Also known as copper oxide. IN ordinary schools(not specializing in) they are studying it. It is a basic oxide, divalent. In nature, copper (II) oxide occurs in the form of the mineral melaconite or it is also called tenorite.
Chemical properties
- Copper (II) oxide decomposes when heated to 1100 ° C:2CuO=2Cu+O2.
- Copper oxide reacts with acids:
CuO+2HNO3=Cu(NO3)2+H2O;
CuO+H2SO4=CuSO4+H2O - copper sulphate.
- When reacting with hydroxides, cuprates are formed:
CuO+2NaOH=Na2CuO2+H2O.
- Reactions of copper(II) oxide with carbon, carbon monoxide, and hydrogen are reduction reactions:
2CuO+C=2Cu+CO2.
CuO+H2=Cu+H2O
Copper (III) oxide - Cu2O3 - copper metal oxide. It is a strong oxidizing agent.
Chemical properties
- Copper(III) oxide is insoluble in water.- Decomposition occurs when exposed to temperature:
2Cu2O3=4CuO+O2 (temperature 400°C).
- During the reaction of copper oxide (III) with hydrogen chloride, chlorine is released;
- When reacting with alkalis, red tetrahydroxocuprates (III) are formed (unstable).
The last two reactions are quite complex, their use is found only in profiling institutions.
note
Most often, copper (II) oxide is used for study. The other two oxides are being studied and used in specialized institutions.
Helpful advice
Copper oxides can cause irritation to the eyes, skin and respiratory tract. Performing various reactions of oxides is allowed only in specially equipped rooms.
Sources:
- Obtaining copper sulfate
Copper (II) hydroxide is a bright blue substance, insoluble in water. It has a crystalline or amorphous structure. This weak base is used in the processing of agricultural plants, in the textile and chemical industries. Cu(OH)₂ is obtained by the action of strong bases (alkalis) on copper salts.
Instruction
Obtaining from copper (II) sulfate
CuSO₄ - white crystalline, soluble in water. When wet or with water, copper sulfate forms a crystalline hydrate (copper (II) sulfate pentahydrate), better known as CuSO₄ 5H₂O. Therefore, in the production of hydroxide, not pure copper sulfate is actually involved, but its crystalline hydrate. Add an alkali (for example NaOH) to this solution and observe the effect of the reaction:
CuSO₄ + 5H₂O + 2NaOH = Na₂SO₄ + Cu(OH)₂↓+5 H₂O.
When a proportional amount of reagents is added, the solution becomes colorless, and the resulting copper hydroxide precipitates as a blue precipitate. Further, this solution can participate in a qualitative reaction to proteins.
The lesson considers an algorithm for compiling an equation for the reactions of oxidation of substances with oxygen. You will learn how to draw diagrams and equations for the reactions of simple and complex substances with oxygen.
Topic: Substances and their transformations
Lesson: Drawing up equations for the reactions of oxidation of substances with oxygen
1. Oxidation of copper with oxygen
When substances are oxidized with oxygen, as a rule, oxides are formed. Consider the procedure for compiling the reaction equation for the oxidation of copper with oxygen, if copper oxide (II) is formed during this reaction.
First, let's write down the reaction scheme: on the left we write down the formulas of the starting materials - copper and oxygen, and on the right - the formula of the reaction product, this is copper (II) oxide. Usually, the name of the resulting product sounds in the formulation of the task, if this formula is ambiguous. So, for example, copper can form two oxides - copper (I) oxide and copper (II) oxide.
Cu + O2 → CuO (reaction scheme)
Now let's arrange the coefficients in the reaction equation:
2Cu + O2 = 2CuO (reaction equation)
Let's consider the second example. Let us compose the reaction equation for the complete combustion of methane in oxygen. Let me remind you that with the complete combustion of substances containing carbon, one of the reaction products is carbon monoxide (IV), i.e. carbon dioxide.
Let's write the reaction scheme. Two substances enter into the reaction - methane and oxygen. Methane is a complex substance; when it is completely burned, oxides of those chemical elements that are part of it are formed. In this case, carbon monoxide (IV) and hydrogen oxide (water) are formed.
CH4 + O2 → CO2 + H2O
Let's place the coefficients in the reaction scheme, we get the reaction equation:
CH4 + 2O2 = CO2 + 2H2O
Fig 1. Combustion of methane in oxygen
3. Combustion of phosphine in oxygen
Let us compose an equation for the combustion reaction of phosphine PH3, if in one of the reaction products the phosphorus valence is equal to V.
Let us write down the formulas of the initial substances - phosphine and oxygen, on the left in the reaction scheme, and the formulas of the reaction products on the right. Phosphine is a complex substance, therefore, during its combustion, oxides of those elements that are part of it are formed - phosphorus (V) oxide and water:
РН3 + О2 → Р2О5 + Н2О
Let's arrange the coefficients in the reaction scheme:
2РН3 + 4О2 = Р2О5 + 3Н2О
1. Collection of tasks and exercises in chemistry: 8th grade: to textbook. P. A. Orzhekovsky and others. “Chemistry. Grade 8» / P. A. Orzhekovsky, N. A. Titov, F. F. Hegele. - M .: AST: Astrel, 2006. (p. 70-74)
2. Ushakova O. V. Chemistry workbook: 8th grade: to the textbook by P. A. Orzhekovsky and others “Chemistry. Grade 8» / O. V. Ushakova, P. I. Bespalov, P. A. Orzhekovsky; under. ed. prof. P. A. Orzhekovsky - M .: AST: Astrel: Profizdat, 2006. (p. 68-70)
3. Chemistry. 8th grade. Proc. for general institutions / P. A. Orzhekovsky, L. M. Meshcheryakova, M. M. Shalashova. – M.: Astrel, 2012. (§21)
4. Chemistry: 8th grade: textbook. for general institutions / P. A. Orzhekovsky, L. M. Meshcheryakova, L. S. Pontak. M.: AST: Astrel, 2005. (§28)
5. Chemistry: inorganic. chemistry: textbook. for 8kl. general inst. /G. E. Rudzitis, F. G. Feldman. - M .: Education, JSC "Moscow textbooks", 2009. (§ 20)
6. Encyclopedia for children. Volume 17. Chemistry / Chapter. ed. V.A. Volodin, leading. scientific ed. I. Leenson. – M.: Avanta+, 2003.
Additional web resources
1. Chemistry tests (online).
2. Unified collection of digital educational resources.
3. Physical and chemical properties of oxygen.
4. Chemical properties.
Homework:
1) with. 72 #5 from the Workbook in Chemistry: 8th grade: to the textbook by P. A. Orzhekovsky and others “Chemistry. Grade 8» / O. V. Ushakova, P. I. Bespalov, P. A. Orzhekovsky; under. ed. prof. P. A. Orzhekovsky - M .: AST: Astrel: Profizdat, 2006.
2) p.128 No. 1,4 from the textbook by P. A. Orzhekovsky, L. M. Meshcheryakova, M. M. Shalashova “Chemistry: 8th grade”, 2013
