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General information about the hydrolysis of copper (II) chloride
DEFINITION
Copper(II) chloride is the average salt formed weak base- copper (II) hydroxide (Cu (OH) 2) and a strong acid - hydrochloric (hydrochloric) (HCl). Formula - CuCl 2.
Represents crystals of yellow-brown (dark brown) color; in the form of crystalline hydrates - green. Molar mass - 134 g / mol.
Rice. 1. Copper (II) chloride. Appearance.
Hydrolysis of copper(II) chloride
Hydrolyzed at the cation. The nature of the medium is acidic. Theoretically, a second step is possible. The hydrolysis equation has the following form:
First stage:
CuCl 2 ↔ Cu 2+ + 2Cl - (salt dissociation);
Cu 2+ + HOH ↔ CuOH + + H + (cation hydrolysis);
Cu 2+ + 2Cl - + HOH ↔ CuOH + + 2Cl - + H + (ionic equation);
CuCl 2 + H 2 O ↔ Cu(OH)Cl + HCl (molecular equation).
Second step:
Cu(OH)Cl ↔ CuOH + + Cl - (salt dissociation);
CuOH + + HOH ↔ Cu(OH) 2 ↓ + H + (cation hydrolysis);
CuOH + + Cl - + HOH ↔ Cu(OH) 2 ↓ + Cl - + H + (ionic equation);
Cu(OH)Cl + H 2 O ↔ Cu(OH) 2 ↓ + HCl (molecular equation).
Examples of problem solving
EXAMPLE 1
EXAMPLE 2
| Exercise | Write down the electrolysis equation for copper (II) chloride solution. What mass of substance will be released on the cathode if 5 g of copper (II) chloride is subjected to electrolysis? |
| Solution | We write the dissociation equation for copper (II) chloride in an aqueous solution: CuCl 2 ↔ Cu 2+ + 2Cl -. We conditionally write the electrolysis scheme: (-) Cathode: Cu 2+ , H 2 O. (+) Anode: Cl -, H 2 O. Cu 2+ +2e → Cu o ; 2Cl - -2e → Cl 2. Then, the electrolysis equation for an aqueous solution of copper (II) chloride will look like this: CuCl 2 \u003d Cu + Cl 2. Calculate the amount of copper (II) chloride substance using the data specified in the problem condition ( molar mass– 134g/mol): υ (CuCl 2) \u003d m (CuCl 2) / M (CuCl 2) \u003d 5/134 \u003d 0.04 mol. According to the reaction equation υ (CuCl 2) \u003d υ (Cu) \u003d 0.04 mol. Then we calculate the mass of copper released at the cathode (molar mass - 64 g / mol): m (Cu) \u003d υ (Cu) × M (Cu) \u003d 0.04 × 64 \u003d 2.56 g. |
| Answer | The mass of copper released at the cathode is 2.56 g. |
§one. Chemical properties of a simple substance (st. ok. = 0).
a) Relation to oxygen.
Unlike its subgroup neighbors, silver and gold, copper reacts directly with oxygen. Copper exhibits little activity towards oxygen, but in humid air it gradually oxidizes and becomes covered with a greenish film, consisting of basic copper carbonates:
In dry air, oxidation is very slow, a thin layer of copper oxide forms on the copper surface:
Outwardly, copper does not change, since copper (I) oxide, like copper itself, Pink colour. In addition, the oxide layer is so thin that it transmits light, i.e. shines through. In a different way, copper oxidizes when heated, for example, at 600-800 0 C. In the first seconds, oxidation goes to copper (I) oxide, which from the surface turns into black copper (II) oxide. A two-layer oxide coating is formed.
Q formation (Cu 2 O) = 84935 kJ.
Figure 2. The structure of the copper oxide film.
b) Interaction with water.
The metals of the copper subgroup are at the end of the electrochemical series of voltages, after the hydrogen ion. Therefore, these metals cannot displace hydrogen from water. At the same time, hydrogen and other metals can displace copper subgroup metals from solutions of their salts, for example:
This reaction is redox, as there is a transfer of electrons:
Molecular hydrogen displaces the metals of the copper subgroup with great difficulty. This is explained by the fact that the bond between hydrogen atoms is strong and a lot of energy is spent on breaking it. The reaction takes place only with hydrogen atoms.
Copper in the absence of oxygen practically does not interact with water. In the presence of oxygen, copper slowly reacts with water and becomes covered with a green film of copper hydroxide and basic carbonate:
c) Interaction with acids.
Being in a series of voltages after hydrogen, copper does not displace it from acids. Therefore, hydrochloric and dilute sulfuric acid do not act on copper.
However, in the presence of oxygen, copper dissolves in these acids to form the corresponding salts:
The only exception is hydroiodic acid, which reacts with copper to release hydrogen and form a very stable copper (I) complex:
2 Cu + 3 HI → 2 H[ CuI 2 ] + H 2
Copper also reacts with acids - oxidizing agents, for example, with nitric acid:
Cu+4HNO 3( conc .) → Cu(NO 3 ) 2 +2NO 2 +2H 2 O
3Cu + 8HNO 3( having diluted .) → 3Cu(NO 3 ) 2 +2NO+4H 2 O
And also with concentrated cold sulfuric acid:
Cu + H 2 SO 4(conc.) → CuO + SO 2 + H 2 O
With hot concentrated sulfuric acid :
Cu+2H 2 SO 4( conc ., hot ) → CuSO 4 + SO 2 + 2H 2 O
With anhydrous sulfuric acid at a temperature of 200 0 C, copper (I) sulfate is formed:
2Cu+2H 2 SO 4( anhydrous .) 200°C → Cu 2 SO 4 ↓+SO 2 + 2H 2 O
d) Relation to halogens and some other non-metals.
Q formation (CuCl) = 134300 kJ
Q formation (CuCl 2) = 111700 kJ
Copper reacts well with halogens, gives two types of halides: CuX and CuX 2 .. Under the action of halogens at room temperature, no visible changes occur, but a layer of adsorbed molecules first forms on the surface, and then a very thin layer of halides. When heated, the reaction with copper is very violent. We heat the copper wire or foil and lower it hot into a jar of chlorine - brown vapors will appear near the copper, consisting of copper (II) chloride CuCl 2 mixed with copper (I) chloride CuCl. The reaction occurs spontaneously due to the release of heat. Monovalent copper halides are obtained by reacting metallic copper with a solution of divalent copper halide, for example:
In this case, the monochloride precipitates out of solution in the form of a white precipitate on the copper surface.
Copper also reacts quite easily with sulfur and selenium when heated (300-400 ° C):
2Cu+S→Cu 2 S
2Cu+Se→Cu 2 Se
But with hydrogen, carbon and nitrogen, copper does not react even at high temperatures.
e) Interaction with oxides of non-metals
When heated, copper can displace simple substances from some non-metal oxides (for example, sulfur (IV) oxide and nitrogen (II, IV) oxides), while forming a thermodynamically more stable copper (II) oxide):
4Cu+SO 2 600-800°C →2CuO + Cu 2 S
4Cu+2NO 2 500-600°C →4CuO + N 2
2 Cu+2 NO 500-600° C →2 CuO + N 2
§2. Chemical properties of monovalent copper (st.c. = +1)
AT aqueous solutions the Cu+ ion is very unstable and disproportionate:
Cu + ↔ Cu 0 + Cu 2+
However, copper in the oxidation state (+1) can be stabilized in compounds with very low solubility or through complexation.
a) Copper oxide (I) Cu 2 O
amphoteric oxide. Brown-red crystalline substance. It occurs naturally as the mineral cuprite. It can be artificially obtained by heating a solution of a copper (II) salt with alkali and some strong reducing agent, for example, formalin or glucose. Copper(I) oxide does not react with water. Copper(I) oxide is transferred into a solution with concentrated hydrochloric acid to form a chloride complex:
Cu 2 O+4 HCl→2 H[ CuCl2]+ H 2 O
We also dissolve in a concentrated solution of ammonia and ammonium salts:
Cu 2 O+2NH 4 + →2 +
In dilute sulfuric acid, it disproportionates to divalent copper and metallic copper:
Cu 2 O+H 2 SO 4(dil.) →CuSO 4 + Cu 0 ↓+H 2 O
Also, copper(I) oxide enters into the following reactions in aqueous solutions:
1. Slowly oxidized by oxygen to copper (II) hydroxide:
2 Cu 2 O+4 H 2 O+ O 2 →4 Cu(Oh) 2 ↓
2. Reacts with dilute hydrohalic acids to form the corresponding copper(I) halides:
Cu 2 O+2 HG→2CuG↓ +H 2 O(G=Cl, Br, J)
3.Reduced to metallic copper with typical reducing agents, for example, sodium hydrosulfite in a concentrated solution:
2 Cu 2 O+2 NaSO 3 →4 Cu↓+ Na 2 SO 4 + H 2 SO 4
Copper(I) oxide is reduced to metallic copper in the following reactions:
1. When heated up to 1800 °C (decomposition):
2 Cu 2 O - 1800° C →2 Cu + O 2
2. When heated in a stream of hydrogen, carbon monoxide, aluminum and other typical reducing agents:
Cu 2 O+H 2 - >250°C →2Cu+H 2 O
Cu 2 O+CO - 250-300°C →2Cu+CO 2
3 Cu 2 O + 2 Al - 1000° C →6 Cu + Al 2 O 3
Also, at high temperatures, copper (I) oxide reacts:
1. With ammonia (copper(I) nitride is formed)
3 Cu 2 O + 2 NH 3 - 250° C →2 Cu 3 N + 3 H 2 O
2. With alkali metal oxides:
Cu 2 O+M 2 O- 600-800°C →2 MCuO (M= Li, Na, K)
In this case, cuprates of copper (I) are formed.
Copper(I) oxide reacts markedly with alkalis:
Cu 2 O+2 NaOH (conc.) + H 2 O↔2 Na[ Cu(Oh) 2 ]
b) Copper hydroxide (I) CuOH
Copper(I) hydroxide forms a yellow substance and is insoluble in water.
Easily decomposes when heated or boiled:
2 CuOH → Cu 2 O + H 2 O
c) HalidesCuF, CuFROMl, CuBrandCuJ
All these compounds are white crystalline substances, poorly soluble in water, but readily soluble in an excess of NH 3 , cyanide ions, thiosulfate ions, and other strong complexing agents. Iodine forms only the compound Cu +1 J. In the gaseous state, cycles of the (CuГ) 3 type are formed. Reversibly soluble in the corresponding hydrohalic acids:
CuG + HG ↔H[ CuG 2 ] (G=Cl, Br, J)
Copper (I) chloride and bromide are unstable in moist air and gradually turn into basic copper (II) salts:
4 CuD +2H 2 O + O 2 →4 Cu(Oh)G (G=Cl, Br)
d) Other copper compounds (I)
1. Copper (I) acetate (CH 3 COOCu) - a copper compound, has the form of colorless crystals. In water, it slowly hydrolyzes to Cu 2 O, in air it oxidizes to divalent copper acetate; CH 3 COOSu is obtained by reduction (CH 3 COO) 2 Cu with hydrogen or copper, sublimation (CH 3 COO) 2 Cu in a vacuum or interaction (NH 3 OH) SO 4 with (CH 3 COO) 2 Cu in p-re in the presence of H 3 COOH 3 . The substance is toxic.
2. Copper(I) acetylenide - red-brown, sometimes black crystals. When dry, the crystals detonate on impact or heat. Wet resistant. Detonation in the absence of oxygen produces no gaseous substances. Decomposes under the action of acids. It is formed as a precipitate when acetylene is passed into ammonia solutions of copper(I) salts:
FROM 2 H 2 +2[ Cu(NH 3 ) 2 ](Oh) → Cu 2 C 2 ↓ +2 H 2 O+2 NH 3
This reaction is used for the qualitative detection of acetylene.
3. Copper nitride - an inorganic compound with the formula Cu 3 N, dark green crystals.
Decomposes on heating:
2 Cu 3 N - 300° C →6 Cu + N 2
Reacts violently with acids:
2 Cu 3 N +6 HCl - 300° C →3 Cu↓ +3 CuCl 2 +2 NH 3
§3. Chemical properties of bivalent copper (st.c. = +2)
The most stable oxidation state of copper and the most characteristic of it.
a) Copper oxide (II) CuO
CuO is the basic oxide of divalent copper. Black crystals, under normal conditions quite stable, practically insoluble in water. In nature, it occurs in the form of the mineral tenorite (melaconite) of black color. Copper(II) oxide reacts with acids to form the corresponding salts of copper(II) and water:
CuO + 2 HNO 3 → Cu(NO 3 ) 2 + H 2 O
When CuO is fused with alkalis, cuprates of copper (II) are formed:
CuO+2 KOH- t ° → K 2 CuO 2 + H 2 O
When heated to 1100 °C, it decomposes:
4CuO- t ° →2 Cu 2 O + O 2
b) Copper (II) hydroxideCu(Oh) 2
Copper(II) hydroxide is a blue amorphous or crystalline substance, practically insoluble in water. When heated to 70-90 ° C, Cu (OH) 2 powder or its aqueous suspensions decompose to CuO and H 2 O:
Cu(Oh) 2 → CuO + H 2 O
It is an amphoteric hydroxide. Reacts with acids to form water and the corresponding copper salt:
It does not react with dilute alkali solutions, but dissolves in concentrated ones, forming bright blue tetrahydroxocuprates (II):
Copper (II) hydroxide with weak acids forms basic salts. It dissolves very easily in excess ammonia to form copper ammonia:
Cu(OH) 2 +4NH 4 OH→(OH) 2 +4H 2 O
Copper ammonia has an intense blue-violet color, so it is used in analytical chemistry to determine small amounts of Cu 2+ ions in solution.
c) Copper salts (II)
Simple salts of copper (II) are known for most anions, except for cyanide and iodide, which, when interacting with the Cu 2+ cation, form covalent copper (I) compounds that are insoluble in water.
Copper salts (+2) are mostly water soluble. The blue color of their solutions is associated with the formation of the 2+ ion. They often crystallize as hydrates. Thus, tetrahydrate crystallizes from an aqueous solution of copper (II) chloride below 15 0 C, trihydrate at 15-26 0 C, and dihydrate above 26 0 C. In aqueous solutions, copper(II) salts are subject to hydrolysis to a small extent, and basic salts often precipitate out of them.
1. Copper (II) sulfate pentahydrate (copper sulfate)
CuSO 4 * 5H 2 O, called copper sulphate, is of the greatest practical importance. Dry salt has a blue color, however, when slightly heated (200 0 C), it loses water of crystallization. Anhydrous white salt. Upon further heating to 700 0 C, it turns into copper oxide, losing sulfur trioxide:
CuSO 4 -- t ° → CuO+ SO 3
Copper sulphate is prepared by dissolving copper in concentrated sulfuric acid. This reaction is described in the section "Chemical Properties of a Simple Substance". Copper sulfate is used in the electrolytic production of copper, in agriculture to control pests and plant diseases, and to obtain other copper compounds.
2. Copper (II) chloride dihydrate.
These are dark green crystals, easily soluble in water. Concentrated solutions of copper chloride have green color, and diluted - blue. This is due to the formation of a green chloride complex:
Cu 2+ +4 Cl - →[ CuCl 4 ] 2-
And its further destruction and the formation of a blue aquacomplex.
3. Copper (II) nitrate trihydrate.
Blue crystalline solid. Obtained by dissolving copper in nitric acid. When heated, the crystals first lose water, then decompose with the release of oxygen and nitrogen dioxide, turning into copper (II) oxide:
2Cu(NO 3 ) 2 -- t° →2CuO+4NO 2 +O 2
4. Hydroxomedi(II) carbonate.
Copper carbonates are unstable and almost never used in practice. Of some importance for the production of copper is only the basic copper carbonate Cu 2 (OH) 2 CO 3, which occurs in nature in the form of the mineral malachite. When heated, it easily decomposes with the release of water, carbon monoxide (IV) and copper oxide (II):
Cu 2 (OH) 2 CO 3 -- t° →2CuO+H 2 O+CO 2
§four. Chemical properties of trivalent copper (st.c. = +3)
This oxidation state is the least stable for copper, and therefore copper(III) compounds are the exception rather than the "rule". However, some trivalent copper compounds exist.
a) Copper oxide (III) Cu 2 O 3
It is a crystalline substance, dark garnet color. Does not dissolve in water.
Obtained by oxidation of copper (II) hydroxide with potassium peroxodisulfate in an alkaline medium at low temperatures:
2Cu(OH) 2 +K 2 S 2 O 8 +2KOH -- -20°C →Cu 2 O 3 ↓+2K 2 SO 4 +3H 2 O
This substance decomposes at a temperature of 400 0 C:
Cu 2 O 3 -- t ° →2 CuO+ O 2
Copper(III) oxide is a strong oxidizing agent. When interacting with hydrogen chloride, chlorine is reduced to free chlorine:
Cu 2 O 3 +6 HCl-- t ° →2 CuCl 2 + Cl 2 +3 H 2 O
b) Copper cuprates (W)
These are black or blue substances, they are not stable in water, they are diamagnetic, the anion is a ribbon of squares (dsp 2). Formed by the interaction of copper (II) hydroxide and alkali metal hypochlorite in an alkaline environment:
2 Cu(Oh) 2 + MClO + 2 NaOH→2MCuO 3 + NaCl +3 H 2 O (M= Na- Cs)
c) Potassium hexafluorocuprate(III)
Green substance, paramagnetic. Octahedral structure sp 3 d 2 . Copper fluoride complex CuF 3, which decomposes in the free state at -60 0 C. It is formed by heating a mixture of potassium and copper chlorides in a fluorine atmosphere:
3KCl + CuCl + 3F 2 → K 3 + 2Cl 2
Decomposes water with the formation of free fluorine.
§5. Copper compounds in oxidation state (+4)
So far, only one substance is known to science, where copper is in the +4 oxidation state, this is cesium hexafluorocuprate (IV) - Cs 2 Cu +4 F 6 - an orange crystalline substance, stable in glass ampoules at 0 0 C. It reacts violently with water. Obtained by fluoridation high pressure and temperature of a mixture of cesium and copper chlorides:
CuCl 2 +2CsCl +3F 2 -- t ° p → Cs 2 CuF 6 +2Cl 2
Basic information:
| Protective, inhibiting fungal spores and pathogens from entering leading tissues |
| Corona yellow body (anhydrous) to blue-green crystals (dihydrate) |
Release:
copper chloride: behavior in the environment
| Index | Meaning | Explanation | ||
| Solubility in water at 20 o C (mg/l) | 757000 Q4 High||||
| Solubility in organic solvents at 20 o C (mg/l) | 680000 Q4 - Methanol -||||
| Melting point (o C) | - - -||||
| Boiling point (o C) | - - -||||
| Decomposition temperature (o C) | - - -||||
| Flash point (o C) | - - -||||
| Partition coefficient in octanol/water at pH 7, 20 o C | P: - - -||||
| Specific gravity (g/ml) / Specific gravity | 3.39Q3-||||
| Dissociation constant (pKa) at 25 o C | - - -||||
| Note: | ||||
| Vapor pressure at 25 o C (MPa) | 1.00 X 10 -10 Q1 Not volatile||||
| Henry's law constant at 25 o C (Pa * m 3 / mol) | - - -||||
| Henry's law constant at 20 o C (dimensionless) | 7.29 X 10 -21 Calculated Not volatile||||
| Decay period in soil (days) | DT50 (typical) - - -||||
| - | ||||
| Aqueous photolysis DT50 (days) at pH 7 | Meaning: - - -||||
| - | ||||
| Aqueous hydrolysis of DT50 (days) at 20 o C and pH 7 | Meaning: - - -||||
| - | ||||
| Water precipitation DT50 (days) | - - -||||
| Water phase only DT50 (days) | - - -||||
| GUS washout potential index | - - -||||
| Concentration growth index in groundwater SCI (µg/l) at an application rate of 1 kg/ha (l/ha) | Meaning: - - -||||
| - | ||||
| Potential for particle bound transport index | - - -||||
| Koc - organic carbon partition coefficient (ml/g) | - - -||||
| pH resistance: | ||||
| Note: | ||||
| Freundlich adsorption isotherm | kf:-- | -|||
| - | ||||
| Maximum UV absorbance (l/(mol*cm)) | - - -||||
copper chloride: ecotoxicity
| Index | Meaning | Source / Qualitative indicators / Other information | Explanation | |
| Bioconcentration coefficient | BCF:-- | -|||
| Bioaccumulative potential | - - -||||
| LD50 (mg/kg) | 140 V3 Rat Moderately||||
| Mammals - Short term food NOEL | (mg/kg): -- | -|||
| Poultry - Acute LD50 (mg/kg) | - - -||||
| Birds - Acute toxicity (CK50 / LD50) | - - -||||
| Fish - Acute 96 hour CK50 (mg/l) | 0.24 F4 Rainbow trout Moderately||||
| Fish - Chronic 21 day NOEC (mg/L) | - - -||||
| Aquatic Invertebrates - Acute 48 hour EC50 (mg/L) | - - -||||
| Aquatic Invertebrates - Chronic 21 day NOEC (mg/L) | - - -||||
| Aquatic crustaceans - Acute 96 hour CK50 (mg/l) | 0.134 F3 mysida shrimp Moderately||||
| Bottom microorganisms - Acute 96 hour CK50 (mg/l) | 0.043 F4 Chironomus mosquito High||||
| NOEC , static, Water (mg/l) | - - -||||
| Bottom microorganisms - Chronic 28 day NOEC , Sedimentary rock (mg/kg) | - - -||||
| Aquatic plants - Acute 7 day EC50 , biomass (mg/l) | - - -||||
| Algae - Acute 72 hour EC50 growth (mg/L) | 0.55 H1 Unknown species Moderate||||
| Algae - Chronic 96 hour NOEC , growth (mg/l) | - - -||||
| Bees - Acute 48 hour LD50 (mcg/individual) | - - -||||
| Earthworms - Acute 14-day CK50 (mg/kg) | - - -||||
| Soil Worms - Chronic 14-Day Maximum Inactive Concentration, Reproduction (mg/kg) | 15 A4 Earthworm, as Cu, 8 week Moderate||||
| Other Arthropods (1) | LR50 (g/ha): - - -||||
| Other Arthropods (2) | LR50 (g/ha): - - -||||
| Soil microorganisms | - - -||||
| Available data on the mesoworld (mesocosm) | NOEAEC mg/l: - - -||||
copper chloride: human health
Main characteristics:
| Index | Meaning | Source / Qualitative indicators / Other information | Explanation | |
| Mammals - Acute oral LD50 (mg/kg) | 140 V3 Rat Moderately||||
| Mammals - Dermal LD50 (mg/kg body weight) | - - -||||
| Mammals - Inhalation | ||||
COPPER AND ITS COMPOUNDS
LESSON IN THE 11th NATURAL SCIENCE CLASS
To increase the cognitive activity and independence of students, we use the lessons of the collective study of the material. At such lessons, each student (or a pair of students) receives a task, the completion of which he must report on in the same lesson, and his report is recorded by the rest of the class in notebooks and is an element of content. educational material lesson. Each student contributes to the study of the topic by the class.
During the lesson, the mode of work of students changes from intraactive (a mode in which information flows are closed within the students, typical for independent work) to interactive (a mode in which information flows are two-way, i.e. information goes both from the student and to the student, information is exchanged). At the same time, the teacher acts as the organizer of the process, corrects and supplements the information provided by the students.
The lessons of collective study of the material consist of the following stages:
1st stage - installation, in which the teacher explains the goals and program of work in the lesson (up to 7 minutes);
Stage 2 - independent work of students according to the instructions (up to 15 minutes);
Stage 3 - exchange of information and summing up the lesson (takes all the remaining time).
The lesson "Copper and its compounds" is designed for classes with in-depth study of chemistry (4 hours of chemistry per week), is held for two academic hours, the lesson updates students' knowledge on the following topics: General properties metals", "Attitude to metals of concentrated sulfuric acid, nitric acid", "Qualitative reactions to aldehydes and polyhydric alcohols", "Oxidation of saturated monohydric alcohols with copper (II) oxide", "Complex compounds".
Before class, students receive homework: repeat the topics listed. The preliminary preparation of the teacher for the lesson consists in compiling instructional cards for students and preparing sets for laboratory experiments.
DURING THE CLASSES
Installation stage
The teacher puts in front of the students the purpose of the lesson: based on existing knowledge about the properties of substances, predict, confirm in practice, generalize information about copper and its compounds.
Students make up the electronic formula of the copper atom, find out what oxidation states copper can exhibit in compounds, what properties (redox, acid-base) copper compounds will have.
A table appears in the students' notebooks.
Properties of copper and its compounds
| Metal | Cu 2 O - basic oxide | CuO - basic oxide |
| Reducing agent | CuOH is an unstable base | Cu (OH) 2 - insoluble base |
| CuCl - insoluble salt | CuSO 4 - soluble salt | |
| Possess redox duality | Oxidizers |
Stage independent work
To confirm and supplement the assumptions, students perform laboratory experiments according to the instructions and write down the equations of the reactions performed.
Instructions for independent work in pairs
1. Ignite the copper wire in a flame. Note how its color has changed. Place the hot calcined copper wire in ethyl alcohol. Note the change in its color. Repeat these manipulations 2-3 times. Check if the smell of ethanol has changed.
Write down two reaction equations corresponding to the transformations carried out. What properties of copper and its oxide are confirmed by these reactions?2. Add hydrochloric acid to copper(I) oxide.
What are you watching? Write down the reaction equations, given that copper (I) chloride is an insoluble compound. What properties of copper(I) are confirmed by these reactions?3. a) Place a zinc granule into the copper(II) sulfate solution. If no reaction occurs, heat the solution. b) Add 1 ml of sulfuric acid to copper (II) oxide and heat.
What are you watching? Write down the reaction equations. What properties of copper compounds are confirmed by these reactions?4. Place a universal indicator strip into the copper(II) sulfate solution.
Explain the result. Write down the ionic equation of hydrolysis for the first stage.
Add a solution of honey(II) sulfate to a solution of sodium carbonate.
What are you watching? write down reaction equation joint hydrolysis in molecular and ionic forms.5.
What are you watching?
Add ammonia solution to the resulting precipitate.
What changes have taken place? Write down the reaction equations. What properties of copper compounds are proved by the reactions carried out?6. Add a solution of potassium iodide to copper(II) sulfate.
What are you watching? Write an equation for the reaction. What property of copper(II) does this reaction prove?7. Place a small piece of copper wire into a test tube with 1 ml of concentrated nitric acid. Close the tube with a stopper.
What are you watching? (Take the test tube under draft.) Write down the reaction equation.
Pour hydrochloric acid into another test tube, place a small piece of copper wire in it.
What are you watching? Explain your observations. What properties of copper are confirmed by these reactions?8. Add an excess of sodium hydroxide to copper(II) sulfate.
What are you watching? Heat up the precipitate. What happened? Write down the reaction equations. What properties of copper compounds are confirmed by these reactions?9. Add an excess of sodium hydroxide to copper(II) sulfate.
What are you watching?
Add a solution of glycerin to the resulting precipitate.
What changes have taken place? Write down the reaction equations. What properties of copper compounds prove these reactions?10. Add an excess of sodium hydroxide to copper(II) sulfate.
What are you watching?
Pour the glucose solution to the resulting precipitate and heat.
What happened? Write the reaction equation using the general formula for aldehydes to denote glucoseWhat property of the copper compound does this reaction prove?
11. Add to copper(II) sulfate: a) ammonia solution; b) sodium phosphate solution.
What are you watching? Write down the reaction equations. What properties of copper compounds are proved by the reactions carried out?
Phase of communication and debriefing
The teacher asks a question concerning the properties of a particular substance. The students who performed the corresponding experiments report on the experiment and write down the reaction equations on the blackboard. Then the teacher and students complete the information about chemical properties ah substances that could not be confirmed by reactions in the conditions of the school laboratory.
The order of discussion of the chemical properties of copper compounds
1. How does copper react with acids, what other substances can copper react with?
The reactions of copper are written with:
Concentrated and dilute nitric acid:
Cu + 4HNO 3 (conc.) = Cu(NO 3) 2 + 2NO 2 + 2H 2 O,
3Cu + 8HNO 3 (diff.) = 3Cu(NO 3) 2 + 2NO + 4H 2 O;
Concentrated sulfuric acid:
Cu + 2H 2 SO 4 (conc.) = CuSO 4 + SO 2 + 2H 2 O;
Oxygen:
2Cu + O 2 \u003d 2CuO;
Cu + Cl 2 \u003d CuCl 2;
Hydrochloric acid in the presence of oxygen:
2Cu + 4HCl + O 2 = 2CuCl 2 + 2H 2 O;
Iron(III) chloride:
2FeCl 3 + Cu \u003d CuCl 2 + 2FeCl 2.
2. What are the properties of copper(I) oxide and chloride?
Attention is drawn to the main properties, the ability to complex formation, redox duality. The equations of reactions of copper (I) oxide with:
Hydrochloric acid to form CuCl:
Cu 2 O + 2HCl = 2CuCl + H 2 O;
Excess HCl:
CuCl + HCl = H;
Reactions of reduction and oxidation of Cu 2 O:
Cu 2 O + H 2 \u003d 2Cu + H 2 O,
2Cu 2 O + O 2 \u003d 4CuO;
Disproportionation when heated:
Cu 2 O \u003d Cu + CuO,
2CuCl \u003d Cu + CuCl 2.
3. What are the properties of copper(II) oxide?
Attention is drawn to the basic and oxidizing properties. Equations for the reactions of copper(II) oxide with:
Acid:
CuO + 2H + = Cu 2+ + H 2 O;
Ethanol:
C 2 H 5 OH + CuO = CH 3 CHO + Cu + H 2 O;
Hydrogen:
CuO + H 2 \u003d Cu + H 2 O;
Aluminum:
3CuO + 2Al \u003d 3Cu + Al 2 O 3.
4. What are the properties of copper(II) hydroxide?
Attention is drawn to the oxidizing, basic properties, the ability to complex with organic and inorganic compounds. The reaction equations are written with:
Aldehyde:
RCHO + 2Cu(OH) 2 = RCOOH + Cu 2 O + 2H 2 O;
Acid:
Cu(OH) 2 + 2H + = Cu 2+ + 2H 2 O;
Ammonia:
Cu (OH) 2 + 4NH 3 \u003d (OH) 2;
Glycerin:
Decomposition reaction equation:
Cu (OH) 2 \u003d CuO + H 2 O.
5. What are the properties of copper(II) salts?
Attention is drawn to the reactions of ion exchange, hydrolysis, oxidizing properties, complexation. The equations for the reactions of copper sulfate are written with:
Sodium hydroxide:
Cu 2+ + 2OH - \u003d Cu (OH) 2;
Sodium Phosphate:
3Cu 2+ + 2= Cu 3 (PO 4) 2;
Cu 2+ + Zn \u003d Cu + Zn 2+;
Potassium iodide:
2CuSO 4 + 4KI = 2CuI + I 2 + 2K 2 SO 4 ;
Ammonia:
Cu 2+ + 4NH 3 \u003d 2+;
and reaction equations:
Hydrolysis:
Cu 2+ + HOH = CuOH + + H + ;
Co-hydrolysis with sodium carbonate to form malachite:
2Cu 2+ + 2 + H 2 O \u003d (CuOH) 2 CO 3 + CO 2.
In addition, you can tell students about the interaction of copper (II) oxide and hydroxide with alkalis, which proves their amphotericity:
Cu (OH) 2 + 2NaOH (conc.) \u003d Na 2,
Cu + Cl 2 \u003d CuCl 2,
Cu + HgCl 2 \u003d CuCl 2 + Hg,
2Cu + 4HCl + O 2 = 2CuCl 2 + 2H 2 O,
CuO + 2HCl \u003d CuCl 2 + H 2 O,
Cu(OH) 2 + 2HCl = CuCl 2 + 2H 2 O,
CuBr 2 + Cl 2 \u003d CuCl 2 + Br 2,
(CuOH) 2 CO 3 + 4HCl \u003d 2CuCl 2 + 3H 2 O + CO 2,
2CuCl + Cl 2 \u003d 2CuCl 2,
2CuCl \u003d CuCl 2 + Cu,
CuSO 4 + BaCl 2 \u003d CuCl 2 + BaSO 4.)
Exercise 3 Make chains of transformations corresponding to the following schemes and carry them out:
Task 1.
An alloy of copper and aluminum was treated first with an excess of alkali and then with an excess of dilute nitric acid. Calculate the mass fractions of metals in the alloy, if it is known that the volumes of gases released in both reactions (under the same conditions) are equal to each other
.
(Answer . Mass fraction of copper - 84%.)
Task 2. On calcination of 6.05 g of hydrated copper(II) nitrate, 2 g of residue was obtained. Determine the formula of the original salt.
(Answer. Cu(NO 3) 2 3H 2 O.)
Task 3. A copper plate weighing 13.2 g was lowered into 300 g of an iron (III) nitrate solution with a mass fraction of salt of 0.112. When it was taken out, it turned out that the mass fraction of iron(III) nitrate became equal to the mass fraction of the formed copper(II) salt. Determine the mass of the plate after it has been removed from the solution.
(Answer. 10 y.)
Homework. Learn the material written in the notebook. Compose a chain of transformations for copper compounds, containing at least ten reactions, and carry it out.
LITERATURE
1. Puzakov S.A., Popkov V.A. A manual on chemistry for university students. Programs. Questions, exercises, tasks. Samples of exam papers. M.: graduate School, 1999, 575 p.
2. Kuzmenko N.E., Eremin V.V. 2000 tasks and exercises in chemistry. For schoolchildren and entrants. M.: 1st Federal Book Trade Company, 1998, 512 p.
Copper chloride 2
Chemical properties
The tool is a binary inorganic substance, belongs to the class salts and halides . It can be considered as a salt formed hydrochloric acid and copper .
Racemic formula of Copper Chloride: CuCl2.
The molecular weight of this compound is 134.5 grams per mole. The substance melts at 498 degrees Celsius. The agent forms crystalline hydrates of the form CuCl2 nH2O .
Used in medicine copper chloride dihydrate.
The product in solid form is yellow-brown crystals. Compound crystalline hydrates depends on the temperature at which crystallization occurs. The substance is highly soluble in ethyl alcohol, water, acetone and methanol .
Reactions of copper chloride
The substance interacts with alkali , thus, as a rule, an insoluble base and a soluble salt are formed. Copper chloride reacts with metals that are located to the left of the metal in the electrochemical series Cu . Also, the compound is characterized by reactions ion exchange with other salts, as a result, an insoluble substance is formed and gas is released.
On an industrial scale, the agent is obtained by the reaction copper oxide 2 with hydrochloric acid or by exchange reaction barium chloride With copper sulphate .
There is also a connection Copper chloride 1 , in which copper is monovalent. Monochloride this metal is a rather toxic compound.
pharmachologic effect
Metabolic.
Pharmacodynamics and pharmacokinetics
Copper is essential for the body. For example, she takes part in a number of chemical reactions occurring in the tissues of the liver. After entering the body, the substance is almost completely metabolized.
Indications for use
Copper chloride solution is part of the solutions used in parenteral nutrition and satisfies the body's need for trace elements .
Contraindications
Preparations containing a solution cannot be used if the patient has substances in the composition, children under 10 years of age. Caution should be observed in renal or hepatic insufficiency.
Side effects
The drug is usually well tolerated by patients. Rarely, nausea and pain at the injection site occur during infusion.
Copper chloride, instructions for use (Method and dosage)
The agent is administered intravenously.
If the drug is initially in the form of a powder, it is diluted in solutions glucose or .
The resulting solution must be used within a day.
The dosage regimen and treatment regimen depend on the drug and the disease.
Overdose
An overdose of the drug occurs rarely. Most often it is used under the supervision of honey. staff and in the hospital.
If a medicine injected too quickly, it may develop: vomiting, sweating, hyperemia skin covers. Reactions disappear after a decrease in the rate of administration of the drug.
Interaction
It is possible to mix the substance in one syringe or package only with r-mi glucose or amino acids , whose concentration does not exceed 50%.
During pregnancy and lactation
The drug can be prescribed to pregnant women.
There is insufficient data on the use of this component during lactation.
Preparations containing (Analogues)
Coincidence in the ATX code of the 4th level:Copper chloride is included in the form of a dihydrate in the composition of the concentrate for the preparation of solutions for infusions Addamel N.
