Halogen compounds. Presentation on the topic "halogen compounds" General characteristics of halogens and their compounds presentation

Express class survey: 1. What elements are called halogens? 2. Describe the position of halogens in the Periodic system of D.I. Mendeleev. 3. What is the structure of halogen atoms? 4. Which of the halogens is the most electronegative? 5. How do the oxidizing properties of halogens change with increasing serial number?

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CFC 1970 Aerosol dispensers Refrigerants Ozone depletion Blindness due to cataracts Skin cancers Suppression of the body's immune system CI + O 3 = CIO + O 2 One chlorine atom destroys O 3 molecules and can last up to 300 years.

Questions Answer options 1) What is common in the structure of halogen atoms: a) the radius of the atom b) the charge of the nucleus c) the number of electrons in the outer layer 2) How does the electronegativity in the group: F-Cl-Br-I: a) decreases b) increases c) does not change 3) Which of the substances taken in pairs can be used to obtain hydrogen chloride: a) NaCl (TV) and H 2 SO 4 (solution) b) NaCl (solution) and H 2 SO 4 (solution) in ) NaCl (TV) and H 2 SO 4 (k) 4) You can distinguish between halogen acids and their salts (except fluorine compounds) using one reagent: a) KCl b) AgNO 3 c) BaSO 4 5) Name the liquid halogen: a ) chlorine b) bromine c) iodine Test

This lesson is a lesson in the assimilation of new knowledge, is based on the presentation, all stages of the lesson are sustained from verification homework before reflection (consolidation of new material). Also contains a video fragment of the experiment "combustion of antimony in chlorine".

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general characteristics halogens public lesson in chemistry in grade 9 Prepared by: Vyskrebentseva S.V. chemistry teacher MBOU secondary school No. 6 st. October

Lesson Objectives: To give an idea of halogens based on their comparative characteristics; Consider simple substances - halogens, their physical and chemical properties; Continue the formation of the ability to compare the properties of simple substances.

Checking homework: testing write out the numbers of properties and characteristics for (1 option) metals, for (2 options) non-metals: Small radius of atoms Large radius of atoms At the outer level from 1 to 3 electrons At the outer level from 4 to 8 electrons Malleability Metallic luster Gaseous state of aggregation Plasticity Various colors Poor electrical conductivity Solid state of aggregation Good thermal conductivity Good electrical conductivity Pronounced reducing properties Pronounced oxidizing properties Allotropy

Correct answers: Metals are characterized by: Small radius of atoms Large radius of atoms At the outer level from 1 to 3 electrons At the outer level from 4 to 8 electrons Malleability Metallic luster Gaseous state of aggregation Plasticity Various colors Poor electrical conductivity Solid state of aggregation Good thermal conductivity Good electrical conductivity Pronounced reduction properties Pronounced oxidizing properties Allotropy

Correct answers: non-metals are characterized by: Small atomic radius Large atomic radius At the outer level from 1 to 3 electrons At the outer level from 4 to 8 electrons Malleability Metallic luster Gaseous state of aggregation Plasticity Various colors Poor electrical conductivity Solid state of aggregation Good thermal conductivity Good electrical conductivity Pronounced reduction properties Pronounced oxidizing properties Allotropy

Chain of transformations: H 2 → NaH → H 2 → HCl NaOH H 2 + 2Na \u003d 2NaH NaH + HCl \u003d NaCl + H 2 H 2 + Cl 2 \u003d 2HCl NaH + H 2 O \u003d NaOH + H 2 2NaOH + 2Al + 6H 2 O \u003d 2Na + 3H 2

Task No. 2 p. 93 Given: Solution: V (air) \u003d 100 l V (O 2) \u003d V (air) * ᵠ (O 2) \u003d 100 * 0.21 \u003d ᵠ (O 2) \u003d 21% 21 l. ᵠ (N 2) \u003d 78% n (O 2) \u003d V / V m \u003d 21 l / 22.4 l / mol \u003d 0.94 mol n (O 2) \u003d? V (N 2) \u003d 100 * 0.78 \u003d 78 l n (N 2) \u003d? n (N 2) \u003d 78l / 22.4l / mol \u003d 3.48mol Answer: 0.94 mol, 3.48 mol.

Problem №3 p.103 Given: Solution: m tech. (WO 3) \u003d 928 kg W (WO 3) \u003d 100% -25% \u003d 75% W (impurity) \u003d 25% m (WO 3) \u003d m those. * W (WO 3) \u003d V (H 2) \u003d? 928kg * 0.75 = 696kg n(W)=? n(WO 3) \u003d m / M \u003d 696 kg / 232 kg / kmol \u003d \u003d 3 kmol WO 3 + 3H 2 \u003d W + 3H 2 O 1 mol 3mol 1mol 3 kmol 9 kmol 3 kmol V (H 2) \u003d nV m \u003d 9 kmol * 22.4 m3 / kmol \u003d 201.6 m3 Answer: 201.6 m3, 3 kmol.

The study of new material: Position in the PSCE and the structure of atoms: VII group main subgroup

General characteristic of halogens: at the external level 7 electrons; the radius of atoms increases; o weaken non-metallic properties; o oxidative capacity is reduced. Fluorine is the strongest oxidizing agent (s.o.-1) For the rest: s.o. -1, +1, +3, +5, +7

Halogens are simple substances Fluorine F 2 is a poisonous light yellow gas with a sharp irritating odor.

Simple substances - halogens 2. Chlorine Cl 2 - a yellow-green gas with a pungent suffocating odor

Simple substances - halogens 3. Bromine Br 2 - brown liquid with a fetid odor

Simple substances - halogens 4. Iodine I 2 - a black-gray solid with a metallic luster and a pungent odor

Chemical properties halogens Interaction with simple substances: a) with hydrogen H 2 H 2 + G 2 \u003d 2NH b) with metals F 2 reacts even with Au, Ag and Pt when heated

Combustion of antimony in chlorine

Chemical properties of halogens 2. Interaction with complex substances: a) with water 2F 2 + 2H 2 O \u003d 4HF + O 2 b) with metal halides Cl 2 → Br 2 → I 2, the oxidizing ability decreases

Homework: Paragraph 18, tasks after paragraph 18 No. 4.5 Paragraph 20, tasks after paragraph 20 No. 1 Thank you for your attention!

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SCENARIO OF AN OPEN LESSON

in chemistry in the 9th grade on the topic:

"GENERAL CHARACTERISTICS OF HALOGENS"

The purpose of the lesson: Give a general description of halogens and consider their physical and

Chemical properties.

Lesson objectives: 1) Continue the formation of skills to compare the properties of simple

Substances;

2) Consolidate general ideas about non-metals and their properties;

3) Develop skills and abilities in solving problems and compiling equations

Chemical reactions involving non-metals.

Lesson type: a lesson in learning new knowledge

Lesson methods: conversation, story, independent work

Equipment: Periodic system of chemical elements D.I. Mendeleev,

Multimedia system, computer.

DURING THE CLASSES:

Organizing time.(1-2 min)

Greeting each other, getting ready for work, communicating the topic and goals of today's lesson.

Checking homework.(10-12 min)

Call 3 people to the board: 1 solves the chain in the middle of the board, 2 people behind the boards solve problems:

Chain of transformations:

H2 → NaH → H2 → HCl

NaOH

H2 + 2Na = 2NaH
NaH + HCl = NaCl + H2
H2 + Cl2 = 2HCl
NaH + H2O = NaOH + H2
2NaOH + 2Al + 6H2O = 2Na + 3H2

Task number 2 p.93

Given: Solution:

V(air)=100 l V(O2)= V(air)* ᵠ (O2)= 100*0.21=

ᵠ (O2)=21% 21 l.

ᵠ (N2) \u003d 78% n (O2) \u003d V / Vm \u003d 21l / 22.4 l / mol \u003d 0.94 mol

N(O2)=? V (N2) \u003d 100 * 0.78 \u003d 78 l

N(N2)=? n (N2) \u003d 78l / 22.4l / mol \u003d 3.48mol

Answer: 0.94 mol, 3.48 mol.

Task number 3 p.103

Given: Solution:

Mtech.(WO3) =928 kg W(WO3) = 100%-25%=75%

W(impurity) = 25% m (WO3) = mtech. *W(WO3)=

V(H2)=? 928kg * 0.75 = 696kg

n(W)=? n(WO3)=m/M=696kg/232kg/kmol = 3 kmol

WO3 + 3H2 = W + 3H2O

1 mol 3 mol 1 mol

3 kmol 9 kmol 3 kmol

V (H2) \u003d nVm \u003d 9 kmol * 22.4 m3 / kmol \u003d 201.6 m3

Answer: 201.6 m3, 3 kmol.

All the rest write a test: select the numbers of properties and characteristics for (1st option) metals, for (2nd option) non-metals:

Small atomic radius
Large atomic radius
At the outer level from 1 to 3 electrons
At the outer level from 4 to 8 electrons
Ductility
metallic luster
Gaseous state of aggregation
Plastic
Various coloring
Poor electrical conductivity
Solid aggregate state
Good thermal conductivity
Good electrical conductivity
Pronounced restorative properties
Pronounced oxidizing properties
Allotropy

Correct answers: 1 option - 2,3,5,6,8,11,12,13,14

Option 2 - 1,4,7,9,10,11,15,16

Learning new material.(20 minutes)

Position in PSCE and the structure of their atoms.

Halogens F, Cl, Br, I, At - elements of the 7th group of the main subgroup of the Periodic Table of Chem. elements.

Fluorine is the strongest oxidizing agent (s.o.-1)

The rest: s.o. -1, +1, +3, +5, +7

In addition to fluorine, chlorine, bromine and iodine in this group there is another element related to halogens - this is astatine. It was predicted by D.I. Mendeleev as eka-iodine, it is a radioactive element, therefore it is not studied in the school course.

Halogens - simple substances and their presence in nature.

Listening to messages about fluorine, chlorine, bromine and iodine. (4 people, focusing on the presentation slides, talk about halogens, the history of their discovery, about the compounds in which they occur in nature) The rest of the class is briefly outlined by the speakers.

Chemical properties of halogens.

Interaction with simple substances:

a) with hydrogen H2

H2 + G2 = 2NG

Fluorine interacts with hydrogen in any conditions with an explosion, chlorine - with an explosion only when ignited or exposed to direct sunlight, bromine reacts with hydrogen only when heated and without an explosion. These reactions are exothermic, while the reaction of iodine with hydrogen is weakly endothermic, it proceeds slowly even when heated.

b) with metals - salts are formed - metal halides.

So fluorine already under normal conditions it reacts with most metals, and when heated it even reacts with Au, Ag and Pt, known for their chemical passivity.

The remaining halogens react with metals mainly when heated. So, in a flask filled with chlorine, crystals of crushed antimony flare up and burn beautifully:

2Sb + 3Cl 2 = 2SbCl 3 (viewing a video fragment of the experiment of antimony with chlorine)

2Sb + 5Cl 2 = 2SbCl 5

An independent task is to write the equations for the reactions of iron with chlorine, copper with bromine.

2. Interaction with complex substances:

a) with water

2F2 + 2H2O = 4HF + O2

b) with metal halides(excl. is fluorine, which primarily interacts with water)

Cl2 → Br2 → I2

oxidizing power decreases from chlorine to iodine:

Cl2 + 2NaBr = 2NaCl + Br2

Br2 + 2KI = 2KBr + I2

Consolidation. (5 minutes.)

Answer 5 test questions on the topic studied (see presentation slides)

Analysis of grades for the lesson.(1 minute.)

Evaluate the d/z who answered at the blackboard and spoke about halogens.

Homework:(1 minute.)

Paragraph 18, tasks after it No. 4.5

Paragraph 20, task after it No. 1

slide 2

Lesson Plan

1. Hydrohalic acids. 2. Hydrochloric acid and its properties. 3. Salts of hydrohalic acids. Halides. Qualitative reactions to halide ions. 4. Natural halogen compounds. 5. Reflection. 6. Summing up. 7. Homework.

slide 3

Hydrogen halides

Н⁺ ª→Г⁻ª Physical properties of NG: HF - liquid HCI, HBr, HI - gases. Toxic!!! Well soluble in water In 1 V water - 517 V HCI 9 18.9984 F Fluorine 17 35.453 Cl Chlorine 35 79.904 Vh Bromine 53 126.904 I Iodine 85 At Astatine Halogens General formula H⁺ G⁻ HF HCI HBr HI K.P.S. HCl Hydrochloric acid

slide 4

Determine the oxidation states of chlorine in its compounds

HClOHClO2HClO3HClO4 Hypochlorous Chloric Perchloric Acid Acid Acid

Slide 5

acids

Hydrofluoric acid - hydrofluoric acid Hydrochloric acid - hydrochloric acid. Hydrobromic acid - HF Hydroiodic acid HCl HBr HI S I L A K I S L O T U V E L I C I V A E T C I F)) +9 2 8 -1 2 Cl))) +17 8 - 1 8 Br)))) 2 +35 18 8 -1 8 2 I))))) +53 8 -1 18 18 8 ??? INCREASE R i o n d e r e c t i o n d e c t i n t i o n

slide 6

Preparation of hydrogen chloride (HCI) synthesis from hydrogen and chlorine Industrial method: NaCl+H2SO4→NaHSO4 +HCl (crystal) (conc.) (crystal) Laboratory method: H2 + Cl2→2HCl Cl2 H2O HCl HCl n2 H2SO4 NaCl H2O HCl

Slide 7

Hydrochloric acid - HCL

Colorless liquid, with a pungent odor, smokes in air M = ? HCl Litmus - red Properties 1. Changes the color of indicators 2. Me (to H2) 3. Basic oxides 5. Salts (weaker acids) 4. Bases Homework: Write reaction equations that confirm the chemical properties of hydrochloric acid

Slide 8

Hydrohalic acids

Slide 9

Qualitative reactions HCL+ AgNO3→ HNO3 + AgCl↓ HBr+ AgNO3→ HNO3 + AgBr↓ HI+ AgNO3→ HNO3 + AgI↓ HF??? CaF2↓ QUALITATIVE REACTIONS

slide 10

Natural halogen compounds

Fluorite is an integral part of apatites and phosphorites, as well as cryolite. Content in the earth's crust (%) F-0.027 Cl-0.045 Br- 0.00016 I–0.00003 kelp Bromides - in sea water, drilling waters of oil wells. Iodides - in sea water, drilling waters of oil wells. NaCl - halite (rock, table salt), KCl - sylvin, (Na, K) Cl - sylvinite. NaBr KBr NaI KI CaF2 NaCl KCl

Slide 11

Salts of hydrohalic acids

M I I R O F T D D I I L O R D D B R O X 1. 2. 4. 3. s 1. Hydroiodic acid salts Horizontal: Vertical: 2. Hydrochloric acid salts 3. Salts of hydrofluoric acid 4. Salts of hydrobromic acid Give names: BaBr2, CaF2, AlCl3, AgI Determine solubility in water

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Halogen compounds

Halogens in nature. Due to their high oxidizing power, halogens are found in nature only in the bound state. The content of halogens in the earth's crust: fluorine - 0.027% chlorine - 0.045% bromine - 0.000 1 6% iodine - 0.0000 3%

Halogens in nature Halite (rock salt) Laminaria See textbook p.86

Hydrogen halides (HH) See textbook § 18, p. 83 Н F hydrogen fluoride +19.5 0 С Н Cl hydrogen chloride -84.8 0 С Н Br gases (excl. H F), with a pungent odor, toxic. t kip Well soluble in water, with the formation of acids.

Hydrohalic acids hydrochloric hydrofluoric hydrobromic hydrochloric hydrofluoric hydroiodic HF HCl HBr HI

Bond length in hydrohalic acid molecules. H Br H I H Cl H F

Hydrohalic acids The strength of acids increases hydrochloric hydrofluoric hydrochloric hydrofluoric hydroiodic HF HCl HBr HI

Hydrogen chloride (HCl) Preparation: NaCl (solid) + H 2 SO 4 (conc.) = NaHSO 4 + HCl Industrial: H 2 + Cl 2 = 2HCl Laboratory: 2NaCl (solid) + H 2 SO 4 (conc. .) = Na 2 SO 4 + 2HCl t Chemical properties: Under normal conditions, hydrogen chloride does not react with metals and their oxides! NaCl? HCl

Hydrochloric acid (HCl) Common with other acids (H +) 2. Interaction with metals. 3. Interaction with basic and amphoteric oxides. 4. Interaction with bases. 5. Interaction with salts. Special properties (Cl -) 2. Interaction with oxidizers (MnO 2 , KMnO 4 , KClO 3 etc.) Chemical properties: 1. Color change of indicators. 1. Interaction with silver nitrate. By dissolving hydrogen chloride in water, a 40% hydrochloric acid solution with a density of 1.19 g/cm3 can be obtained. Receipt:

Application of hydrochloric acid See textbook p. 85 fig. 19

Salts of hydrohalic acids Qualitative reactions. fluorides chlorides bromides iodides Me F Me Br Me I Me Cl Cl - F - Br - I - + Ag + = AgCl + Ag + = AgBr + Ag + = AgI + Ca 2+ = CaF 2 white white Light yellow yellow 2

Solve the chain, write ionic equations for the exchange reactions, name the substances in the chain. 1 option. I 2 HI NaI AgI Br 2 HBr KBr AgBr 2 option.

Homework. § 18, ex. 2 (oral), ex. 4 (letter), arrange laboratory work.

Frosted glass in everyday life Glass doors Office decoration

Degtyareva M.O.

Moscow region

Korolev AOU LNIP

The elements of group VII, the main subgroup, include

fluorine F , chlorine Cl , bromine Br , iodine I , astatine At

Common name - halogens ( Greek . "salt-forming" ) - most of their compounds with metals are typical salts (KCl, NaCl, etc.).

Fluorite CaF 2

Halite NaCl

C ilvinite

KCl NaCl

Atom radius

Electronegativity

Oxidizing properties

Non-metallic properties

Fluorine

Chlorine

Bromine

2 s 2 2p 5

Astatine

3 s 2 3 p 5

4 s 2 4 p 5

5 s 2 5 p 5

6 s 2 6 p 5

+ 9

2 7

2 8 7

2 8 18 7

2 8 18 18 7

2 8 18 32 18 7

Name "fluorine" (from the Greek phthoros - destruction, death)

In the free state, fluorine was obtained on June 26, 1886 by the French chemist Moissan.

It is a greenish-yellow gas, slightly heavier than air, with a characteristic odor and unusual chemical activity.

None of the chemical elements

brought chemists so many tragic

events like fluorine .

Chlorine was discovered by the Swedish chemist Carl Scheele in 1774.

In 1810, Sir Humphrey Davy named the gas Chlorine, from the Greek for green.
This term is used in English,

and in other languages the name "chlorine" was fixed.

Yellow-green gas with a pungent odor, poisonous
2.5 times heavier than air
about 2 volumes of chlorine dissolve in 1 volume of water at 20 °C

79 Br ( 50,56% ) 81 Br ( 49,44% )

from the Greek bromos- stench
the only non-metal that is liquid at room temperature

heavy red-brown liquid with an unpleasant odor

bromine vapor has a yellow-brown color
at -7.25°C, bromine solidifies, turning into red-brown acicular crystals with a slight metallic sheen

from the Greek iodes - having a violet color
it passes into the vapor state at room temperature without melting (sublimation);
couples - purple

12 6,9

Iodine was discovered in 1811 by Courtois in the ashes of seaweed, and from 1815 Gay-Lussac began to consider it as a chemical element

There are 37 known isotopes of iodine with mass numbers from 108 to 144.