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General information on the hydrolysis of copper (II) chloride
DEFINITION
Copper (II) chloride - a medium salt formed by a 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. The molar mass is 134 g / mol.
Figure: 1. Chloride of copper (II). Appearance.
Hydrolysis of copper (II) chloride
Hydrolyzed by cation. The nature of the environment is sour. A second stage is theoretically possible. The hydrolysis equation is as follows:
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 stage:
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
| The task | 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? |
| Decision | Let us write the equation for the dissociation of copper (II) chloride in an aqueous solution: CuCl 2 ↔ Cu 2+ + 2Cl -. Let's conditionally write down 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 equation of electrolysis of an aqueous solution of copper (II) chloride will look like this: CuCl 2 \u003d Cu + Cl 2. We calculate the amount of copper (II) chloride substance using the data specified in the problem statement (molar mass - 134 g / 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 2.56g. |
| Answer | The mass of copper released at the cathode is 2.56 g. |
§1. Chemical properties of a simple substance (st. Approx. \u003d 0).
a) Relationship to oxygen.
Unlike its subgroup neighbors - silver and gold - copper reacts directly with oxygen. Copper exhibits insignificant 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 proceeds very slowly, the thinnest layer of copper oxide forms on the copper surface:
Externally, copper does not change at the same time, since copper (I) oxide, like copper itself, is pink in color. In addition, the oxide layer is so thin that it transmits light, i.e. shines through. Copper oxidizes in a different way when heated, for example, at 600-800 0 C. In the first seconds, oxidation proceeds to copper (I) oxide, which transforms from the surface into black copper (II) oxide. A two-layer oxide coating is formed.
Q formation (Cu 2 O) \u003d 84935 kJ.
Figure 2. Structure of a copper oxide film.
b) Interaction with water.
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 metals of the copper subgroup from solutions of their salts, for example:
This reaction is redox, as the transition of electrons occurs:
Molecular hydrogen displaces 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 goes only with hydrogen atoms.
In the absence of oxygen, copper practically does not interact with water. In the presence of oxygen, copper slowly interacts with water and becomes covered with a green film of copper hydroxide and basic carbonate:
c) Interaction with acids.
Being in the series of stresses after hydrogen, copper does not displace it from acids. Therefore, hydrochloric and dilute sulfuric acid does not affect copper.
However, in the presence of oxygen, copper dissolves in these acids with the formation of 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( end .) → Cu (NO 3 ) 2 + 2NO 2 + 2H 2 O
3Cu + 8HNO 3( dilute .) → 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( end ., hot ) → CuSO 4 + SO 2 + 2H 2 O
With anhydrous sulfuric acid at a temperature of 200 ° C, copper (I) sulfate is formed:
2Cu + 2H 2 SO 4( waterless .) 200 ° C → Cu 2 SO 4 ↓ + SO 2 + 2H 2 O
d) Relation to halogens and some other non-metals.
Formation Q (CuCl) \u003d 134300 kJ
Q formation (CuCl 2) \u003d 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 forms on the surface first, and then a thinnest layer of halides. When heated, the reaction with copper is very violent. We heat a copper wire or foil and lower it hot into a jar with chlorine - brown vapors will appear near copper, consisting of copper (II) chloride CuCl 2 with an admixture of copper (I) chloride CuCl. The reaction occurs spontaneously due to the released heat. Monovalent copper halides are obtained by reacting metallic copper with a solution of a divalent copper halide, for example:
In this case, the monochloride falls out of solution in the form of a white precipitate on the copper surface.
Copper also quite easily steps into reaction with sulfur and selenium when heated (300-400 ° C):
2Cu + S → Cu 2 S
2Cu + Se → Cu 2 Se
But copper does not react with hydrogen, carbon and nitrogen even at high temperatures.
e) Interaction with non-metal oxides
When heated, copper can displace simple substances from some oxides of non-metals (for example, sulfur (IV) oxide and nitrogen oxides (II, IV)), thus 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 cuprous copper (st.ok. \u003d +1)
In 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 by complexation.
a) Copper oxide (I) Cu 2 O
Amphoteric oxide. The crystalline substance is brownish-red. It occurs naturally in the form of the mineral cuprite. It can be artificially obtained by heating a solution of a copper (II) salt with an 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 will also dissolve in a concentrated solution of ammonia and ammonium salts:
Cu 2 O + 2NH 4 + →2 +
In dilute sulfuric acid, it disproportionates into 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 with 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 \u003dCl, Br, J)
3.Reduced to metallic copper by 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 to 1800 ° C (decomposition):
2 Cu 2 O - 1800 ° C →2 Cu + O 2
2. When heated in a stream of hydrogen, carbon monoxide, with aluminum and other typical reducing agents:
Cu 2 O + H 2 - \u003e 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 \u003d Li, Na, K)
This results in the formation of copper (I) cuprates.
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, does not dissolve in water.
Readily decomposes when heated or boiled:
2 CuOH → Cu 2 O + H 2 O
c) HalidesCuF, CuFROMl, CuBr andCuJ
All these compounds are white crystalline substances that are 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 (CuH) 3 type are formed. Reversibly soluble in the corresponding hydrohalic acids:
CuG + HG ↔H[ CuD 2 ] (Г \u003dCl, Br, J)
Chloride and bromide of copper (I) are unstable in humid air and gradually turn into basic copper (II) salts:
4 CuG +2H 2 O + O 2 →4 Cu(OH) Г (Г \u003d Cl, Br)
d) Other copper compounds (I)
1. Copper (I) acetate (СН 3 СООСu) - a copper compound, has the form of colorless crystals. In water, it slowly hydrolyzes to Cu 2 O; in air, it oxidizes to bivalent copper acetate; CH 3 COOCu is obtained by reduction of (CH 3 COO) 2 Cu with hydrogen or copper, by sublimation (CH 3 COO) 2 Cu in vacuum or by the interaction of (NH 3 OH) SO 4 with (CH 3 COO) 2 Cu in solution in the presence of H 3 COONH 3. The substance is toxic.
2. Copper (I) acetylenide - red-brown, sometimes black crystals. In dry form, crystals detonate upon impact or heating. Stable when wet. During detonation in the absence of oxygen, no gaseous substances are formed. Decomposes under the action of acids. 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.ok. \u003d +2)
The most stable oxidation state for copper and the most characteristic for it.
a) Copper oxide (II) CuO
CuO is the basic bivalent copper oxide. The crystals are black in color, quite stable under normal conditions, practically insoluble in water. It occurs naturally in the form of black tenorite (melaconite) mineral. Copper (II) oxide reacts with acids to form the corresponding copper (II) and water salts:
CuO + 2 HNO 3 → Cu(NO 3 ) 2 + H 2 O
When CuO fusion with alkalis, copper (II) cuprates are formed:
CuO+2 KOH- t ° → K 2 CuO 2 + H 2 O
When heated to 1100 ° C 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 decomposes 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 solutions of alkalis, in concentrated solutions it dissolves, forming bright blue tetrahydroxocuprates (II):
Copper (II) hydroxide forms basic salts with weak acids. It dissolves very easily in an excess of ammonia to form copper ammonia:
Cu (OH) 2 + 4NH 4 OH → (OH) 2 + 4H 2 O
Copper ammoniaate has an intense blue-violet color; therefore, it is used in analytical chemistry to determine small amounts of Cu 2+ ions in solution.
c) Copper salts (II)
Simple copper (II) salts are known for most anions, except for cyanide and iodide, which, when interacting with the Cu 2+ cation, form covalent copper (I) compounds, 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. So, from an aqueous solution of copper (II) chloride below 15 ° C, tetrahydrate crystallizes, at 15-26 ° C - trihydrate, above 26 ° C - dihydrate. In aqueous solutions, copper (II) salts are slightly hydrolyzed, and basic salts are often precipitated from them.
1. Copper (II) sulfate pentahydrate (copper sulfate)
CuSO 4 * 5H 2 O, called copper sulfate, is of the greatest practical importance. Dry salt has a blue color, however, with slight heating (200 0 С), it loses crystallization water. Anhydrous white salt. Upon further heating to 700 0 С, it turns into copper oxide, losing sulfur trioxide:
CuSO 4 -- t ° → CuO+ SO 3
Copper sulfate 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 combat pests and plant diseases, to obtain other copper compounds.
2. Copper (II) chloride dihydrate.
These are dark green crystals, readily soluble in water. Concentrated copper chloride solutions are green, and dilute solutions are 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 aqua complex.
3. Copper (II) nitrate trihydrate.
Blue crystalline substance. It is 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. Hydroxomed (II) carbonate.
Copper carbonates are unstable and are 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 naturally in the form of the mineral malachite. When heated, it easily decomposes with the release of water, carbon monoxide (IV) and copper (II) oxide:
Cu 2 (OH) 2 CO 3 -- t ° → 2CuO + H 2 O + CO 2
§4. Chemical properties of trivalent copper (st.ok. \u003d +3)
This oxidation state is the least stable for copper, and therefore copper (III) compounds are the exceptions rather than "rules". However, some trivalent copper compounds do exist.
a) Copper (III) oxide Cu 2 O 3
It is a crystalline substance, dark garnet color. Does not dissolve in water.
It is obtained by oxidation of copper (II) hydroxide with potassium peroxodisulfate in an alkaline medium at negative 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 С:
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) Cuprates of copper (III)
These are black or blue substances, unstable in water, diamagnetic, anion - ribbons of squares (dsp 2). Formed by the interaction of copper (II) hydroxide and alkali metal hypochlorite in an alkaline medium:
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 a free state at -60 0 С. 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 to form free fluorine.
§five. Copper compounds in the oxidation state (+4)
So far, science knows only one substance where copper is in the +4 oxidation state, this is cesium hexafluorocuprate (IV) - Cs 2 Cu +4 F 6 - an orange crystalline substance that is stable in glass ampoules at 0 0 C. Reacts violently with water. It is obtained by fluorination at 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 the entry of leading tissues |
| Corona corpus luteum (anhydrous) to blue-green crystals (dihydrate) |
Release:
copper chloride: behavior in the environment
| Index | Value | 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) | - - -||||
| Evaporating temperature (o C) | - - -||||
| Decomposition temperature (o C) | - - -||||
| Flash point (o C) | - - -||||
| Partition coefficient in the octanol / water system at pH 7, 20 o C | P: - - -||||
| Specific gravity (g / ml) / Specific gravity | 3.39 Q3 -||||
| 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) - - -||||
| - | ||||
| DT50 water photolysis (days) at pH 7 | Value: - - -||||
| - | ||||
| Aqueous hydrolysis of DT50 (days) at 20 o C and pH 7 | Value: - - -||||
| - | ||||
| DT50 water deposition (days) | - - -||||
| Only water phase DT50 (days) | - - -||||
| Potential washout index GUS | - - -||||
| SCI concentration growth index in groundwater (μg / l) at an application rate of 1 kg / ha (l / ha) | Value: - - -||||
| - | ||||
| Potential for particle bound transport index | - - -||||
| Koc - distribution coefficient of organic carbon (ml / g) | - - -||||
| pH stability: | ||||
| Note: | ||||
| Freundlich adsorption isotherm | Kf: -- | -|||
| - | ||||
| Maximum UV absorption (l / (mol * cm)) | - - -||||
copper chloride: ecotoxicity
| Index | Value | Source / Qualitative indicators / Other information | Explanation | |
| Bioconcentration factor | BCF: -- | -|||
| Bioaccumulation potential | - - -||||
| LD50 (mg / kg) | 140 V3 Rat Moderate||||
| Mammals - Short-period food NOEL | (mg / kg): -- | -|||
| Birds - Acute LD50 (mg / kg) | - - -||||
| Birds - Acute toxicity (CK50 / LD50) | - - -||||
| Fish - Acute 96 hours CK50 (mg / l) | 0.24 F4 Rainbow trout Moderately||||
| Fish - Chronic 21 days NOEC (mg / L) | - - -||||
| Aquatic invertebrates - Acute 48 hour EC50 (mg / L) | - - -||||
| Aquatic invertebrates - Chronic 21 days NOEC (mg / L) | - - -||||
| Aquatic Crustaceans - Acute 96 Hour CK50 (mg / L) | 0.134 F3 Shrimp-mysida Moderately||||
| Bottom microorganisms - Acute 96 h CK50 (mg / l) | 0.043 F4 Chironomus mosquito Tall||||
| NOEC, static, Water (mg / l) | - - -||||
| Bottom microorganisms - Chronic 28 day NOEC, Sedimentary rock (mg / kg) | - - -||||
| Aquatic plants - Acute 7 days 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 (μg / specimen) | - - -||||
| Soil Worms - Acute 14-day CK50 (mg / kg) | - - -||||
| Soil worms - Chronic 14-day maximum inactive concentration of the substance, 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
Basic indicators:
| Index | Value | Source / Qualitative indicators / Other information | Explanation | |
| Mammals - Acute oral LD50 (mg / kg) | 140 V3 Rat Moderate||||
| Mammals - Cutaneous LD50 (mg / kg bw) | - - -||||
| Mammals - Inhalation | ||||
COPPER AND ITS COMPOUNDS
LESSON IN THE 11TH NATURAL SCIENTIFIC CLASS
To increase the cognitive activity and independence of students, we use the lessons of collective study of the material. In such lessons, each student (or a pair of students) receives an assignment, the completion of which he must report on in the same lesson, and his report is recorded by the rest of the students in the class in notebooks and is an element of the content of the teaching material of the lesson. Each student contributes to the study of the topic in the classroom.
During the lesson, the work mode of students changes from intraactive (the mode in which information flows are closed inside the learners, typical for independent work) to interactive (the mode in which information flows are two-sided, i.e. information goes from both 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 the collective study of the material consist of the following stages:
1st stage - setting, in which the teacher explains the goals and program of work in the lesson (up to 7 minutes);
2nd stage - students' independent work according to the instructions (up to 15 minutes);
3rd stage - exchange of information and summing up the results of 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 actualizes the knowledge of students on the following topics: "General properties of metals", "Attitude towards metals with concentrated sulfur acids, nitric acid ”,“ Qualitative reactions to aldehydes and polyhydric alcohols ”,“ Oxidation of saturated monohydric alcohols with copper (II) oxide ”,“ Complex compounds ”.
Before the lesson, students receive homework: review the listed topics. The preliminary preparation of the teacher for the lesson consists of drawing up instruction cards for students and preparing kits for laboratory experiments.
DURING THE CLASSES
Installation stage
The teacher puts before the students the purpose of the lesson: based on existing knowledge about the properties of substances, predict, confirm in practice, summarize information about copper and its compounds.
Students compose 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 - unstable base | Cu (OH) 2 - insoluble base |
| CuCl - insoluble salt | CuSO 4 - soluble salt | |
| Have a redox duality | Oxidants |
Stage of 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 self-study in pairs
1. Heat the copper wire in a flame. Note how its color has changed. Place the hot annealed copper wire in ethyl alcohol. Note the change in color. Repeat these manipulations 2-3 times. Check if the ethanol smell has changed.
Write down two reaction equations corresponding to the performed transformations. What properties of copper and its oxide are confirmed by these reactions?2. Add hydrochloric acid to copper oxide (I).
What are you watching? Write down the reaction equations, taking into account that copper (I) chloride is an insoluble compound. What properties of copper (I) are confirmed by these reactions?3. a) Place a zinc granule in a copper (II) sulfate solution. If the reaction does not proceed, 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 the multi-indicator strip in the copper (II) sulfate solution.
Explain the result. Write down the ionic equation of hydrolysis for stage I.
Add honey (II) sulfate solution to the sodium carbonate solution.
What are you watching? Write down the equation for the reaction of joint hydrolysis in molecular and ionic forms.5.
What are you watching?
Pour the ammonia solution to the resulting precipitate.
What changes have occurred? Write down the reaction equations. What properties of copper compounds are proved by the conducted reactions?6. Add potassium iodide solution to copper (II) sulfate.
What are you watching? Write the reaction equation. What property of copper (II) does this reaction prove?7. Place a small piece of copper wire in 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 the draft.) Write down the reaction equation.
Pour hydrochloric acid into another tube, put a small piece of copper wire in it.
What are you watching? Explain your observations. What properties of copper are supported by these reactions?8. Add excess sodium hydroxide to copper (II) sulfate.
What are you watching? Heat the resulting precipitate. What happened? Write down the reaction equations. What properties of copper compounds are confirmed by these reactions?9. Add excess sodium hydroxide to copper (II) sulfate.
What are you watching?
Pour glycerin solution to the resulting sediment.
What changes have occurred? Write down the reaction equations. What properties of copper compounds do these reactions prove?10. Add excess sodium hydroxide to copper (II) sulfate.
What are you watching?
Pour glucose solution to the resulting sediment and heat.
What happened? Write down the reaction equation using the general formula for aldehydes for 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 conducted reactions?
Information exchange and debriefing phase
The teacher asks a question regarding the properties of a particular substance. Students who have performed the corresponding experiments report on the experiment and write down the reaction equations on the board. Then the teacher and the students add information about the chemical properties of the substance, which could not be confirmed by reactions in the conditions of the school laboratory.
Procedure for discussing the chemical properties of copper compounds
1. How does copper react with acids, with what other substances can copper react?
The reaction equations for copper are written with:
Concentrated and diluted nitric acid:
Cu + 4HNO 3 (conc.) \u003d Cu (NO 3) 2 + 2NO 2 + 2H 2 O,
3Cu + 8HNO 3 (dil.) \u003d 3Cu (NO 3) 2 + 2NO + 4H 2 O;
Concentrated sulfuric acid:
Cu + 2H 2 SO 4 (conc.) \u003d CuSO 4 + SO 2 + 2H 2 O;
Oxygen:
2Cu + O 2 \u003d 2CuO;
Cu + Cl 2 \u003d CuCl 2;
With hydrochloric acid in the presence of oxygen:
2Cu + 4HCl + O 2 \u003d 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 basic properties, ability to form complexation, redox duality. The equations of reactions of copper (I) oxide are written with:
With hydrochloric acid to form CuCl:
Cu 2 O + 2HCl \u003d 2CuCl + H 2 O;
Excessive HCl:
CuCl + HCl \u003d H;
Reduction and oxidation reactions of Cu 2 O:
Cu 2 O + H 2 \u003d 2Cu + H 2 O,
2Cu 2 O + O 2 \u003d 4CuO;
Heating disproportionation:
Cu 2 O \u003d Cu + CuO,
2CuCl \u003d Cu + CuCl 2.
3. What properties does copper (II) oxide exhibit?
Attention is paid to the basic and oxidizing properties. The equations of the reactions of copper (II) oxide with:
Acid:
CuO + 2H + \u003d Cu 2+ + H 2 O;
Ethanol:
C 2 H 5 OH + CuO \u003d 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 form complexation with organic and inorganic compounds. The equations of reactions are written with:
Aldehyde:
RCHO + 2Cu (OH) 2 \u003d RCOOH + Cu 2 O + 2H 2 O;
Acid:
Cu (OH) 2 + 2H + \u003d 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 with:
Sodium hydroxide:
Cu 2+ + 2OH - \u003d Cu (OH) 2;
Sodium Phosphate:
3Cu 2+ + 2 \u003d Cu 3 (PO 4) 2;
Cu 2+ + Zn \u003d Cu + Zn 2+;
Potassium iodide:
2CuSO 4 + 4KI \u003d 2CuI + I 2 + 2K 2 SO 4;
Ammonia:
Cu 2+ + 4NH 3 \u003d 2+;
and the reaction equations:
Hydrolysis:
Cu 2+ + HOH \u003d CuOH + + H +;
Joint 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 \u003d 2CuCl 2 + 2H 2 O,
CuO + 2HCl \u003d CuCl 2 + H 2 O,
Cu (OH) 2 + 2HCl \u003d 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:
Objective 1.
The copper-aluminum alloy 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%.)
Objective 2. Calcining 6.05 g of copper (II) nitrate crystalline hydrate yielded 2 g of a residue. Determine the formula of the original salt.
(Answer. Cu (NO 3) 2 3H 2 O.)
Objective 3. A copper plate weighing 13.2 g was immersed in 300 g of a solution of iron (III) nitrate 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 removing it from the solution.
(Answer. 10 g)
Homework. Learn the material written in the notebook. Make up a chain of transformations for copper compounds, containing at least ten reactions, and carry it out.
LITERATURE
1. Puzakov S.A., Popkov V.A. Chemistry manual for university applicants. Programs. Questions, exercises, tasks. Samples of exam tickets. M .: Higher school, 1999, 575 p.
2. Kuzmenko N.E., Eremin V.V. 2000 tasks and exercises in chemistry. For schoolchildren and applicants. M .: 1st Federal Bookselling Company, 1998, 512 p.
Copper chloride 2
Chemical properties
The tool is a binary inorganic thing, belongs to the class salts and halides ... It can be thought of as the 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 product forms crystalline hydrates of the form CuCl2 nH2O .
In medicine they use copper chloride dihydrate.
Solid form agent - yellow-brown crystals. Composition crystal hydrates depends on the temperature at which crystallization occurs. The substance is highly soluble in ethyl alcohol, water, acetone and methanol .
Copper Chloride Reactions
The substance interacts with alkali this generally forms an insoluble base and a soluble salt. Copper Chloride reacts with metals that are located to the left of the metal in the electrochemical series Cu ... Also, the compound has 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 reaction Copper oxide 2 with hydrochloric acid or by exchange reaction Barium chloride from Copper sulfate .
There is also a connection Copper chloride 1 , in which copper is monovalent. Monochloride this metal is a fairly toxic compound.
pharmachologic effect
Metabolic.
Pharmacodynamics and pharmacokinetics
Copper is essential for the body. For example, it takes part in a number of chemical reactions in the liver tissues. After entering the body, the substance is almost completely metabolized.
Indications for use
A solution of Copper Chloride is included in the composition of solutions used in parenteral nutrition , and satisfies the body's need for trace elements .
Contraindications
Preparations that contain a solution cannot be used if the patient has substances in the composition, for children under 10 years of age. Caution should be observed in renal or hepatic impairment.
Side effects
Usually the medicine is well tolerated by patients. Rarely, during the infusion, nausea and soreness occurs at the injection site.
Copper chloride, application instruction (Way 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 24 hours.
The dosage regimen and treatment regimen depend on the drug and the disease.
Overdose
Drug overdose is rare. Most often it is used under the supervision of honey. staff and in the hospital.
If the drug is administered too quickly, it may develop: vomiting, sweating, hyperemia skin. Reactions take place after reducing the rate of drug administration.
Interaction
It is possible to mix a substance in one syringe or bag only with r-mi glucose or amino acids , the concentration of which does not exceed 50%.
During pregnancy and lactation
The remedy can be administered to pregnant women.
There is insufficient data on the use of this component during breastfeeding.
Preparations that contain (Analogues)
Matching ATX level 4 code:Copper Chloride is included in the form of a dihydrate in the concentrate for the preparation of solutions for infusion Addamel N.
