home Exchange rates Presentations on the topic of pure substances and mixtures. Presentation for the lesson Pure substances and mixtures presentation for a chemistry lesson (8th grade) on the topic

Presentations on the topic of pure substances and mixtures. Presentation for the lesson Pure substances and mixtures presentation for a chemistry lesson (8th grade) on the topic

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Slide captions:

PURE SUBSTANCES MIXTURES

WORK PLAN Characteristics of the substance: according to different types classification; 2. The concept of “pure substance” and “mixture”: characteristics of the concepts; qualification of pure substances; classification of mixtures; 3. Experimental work. Conclusions.

Characteristics of a substance BY COMPOSITION BY AGREGATE STATE BY PHYSICAL PROPERTIES

Differences in the properties of substances Internet resource http://www.alhimik.ru / teleclass / tests /test003.htm

PURE SUBSTANCES MIXTURES

PURE SUBSTANCE MIXTURE

A PURE SUBSTANCE A MIXTURE CONSISTS OF IDENTICAL PARTICLES (ATOMS, MOLECULES, IONS)

A PURE SUBSTANCE A MIXTURE CONSISTS OF IDENTICAL PARTICLES (ATOMS, MOLECULES, IONS) CONSISTS OF SEVERAL DIFFERENT SUBSTANCES

According to the current regulations in Russia, the following qualifications have been established for reagents: pure (pure grade), pure for analysis (analytical grade), chemically pure (reagent grade), extra pure (extra pure grade)

EXPERIMENT Safe work rules! TASK: 1) PREPARATION OF THE MIXTURE; 2) STUDY OF THE PROPERTIES OF THE MIXTURE.

MIXTURES OF HOMOS - GENE (similar) HETEROGENEOUS (heterogeneous)

oxygen O 2 hydrogen H 2 water H 2 O pure, simple substances complex substance mixture: homogeneous; heterogeneous

WHAT SUBSTANCE ARE WE TALKING ABOUT? In living cells and depths Life gives to hemoglobin. He is a courageous metal, but he is in a side group. And especially personal pride - It’s made of excellent steel! Fe

WHAT SUBSTANCE ARE WE TALKING ABOUT? Yellow, sunny, beautiful Non-metal. How famous! It has lived in the world for hundreds of years and is used in medicine. With hydrogen it is terrible, poisonous and... oh, dangerous! All living beings die twice or twice. S

EXPERIMENT Substances: IRON - Fe SULFUR - S TASK: CHARACTERISTICS OF THE PHYSICAL PROPERTIES OF SUBSTANCES; 2) PREPARATION OF THE MIXTURE; 3) STUDY OF THE PROPERTIES OF THE MIXTURE.

Comparative characteristics mixture and pure substance Comparison characteristics Pure substance Mixture Composition Substances Physical properties Separation

Comparative characteristics of a mixture and a pure substance Signs of comparison Pure substance Mixture Composition Constant Variable (variable) Substances Physical properties Separation

Comparative characteristics of a mixture and a pure substance Signs of comparison Pure substance Mixture Composition Constant Variable (variable) Substances One and the same Different Physical properties Separation

Lesson summary 1. Concepts: “pure substance” qualification of pure substances; “mixture” classification of mixtures; 2. Studied the properties of substances in the mixture

please put it in order workplace! Thank you for your work!

Lesson objectives:

To figure out:

Which substance is considered pure?
What is a mixture?
What types of mixtures are there?
In what ways can a mixture be separated?

Definition of “mixture”

was given in the 17th century. English scientist Robert Boyle:

“A mixture is an integral system consisting of heterogeneous components.”

Comparative characteristics pure substance and mixture

Signs of comparison

Pure substance

Compound

Mixture

Constant

Substances

Same

Fickle

Physical properties

Energy change during formation

Various

Permanent

Happening

Fickle

Separation

Not happening

Through chemical reactions

By physical methods

They call them clean substances that have a constant composition and constant physical properties.

Mixture is a combination of different substances.

distinctive feature of mixtures

In mixtures, each of the constituent substances retains its individual properties.

These are mixtures in which particles of substances are visible to the naked eye.

These are mixtures in which particles of substances cannot be seen.

Homogeneous

Heterogeneous

suspensions

liquid

emulsions

Gaseous

hard

Test your knowledge Name the pure ones from the proposed substances:

Water in the river
Water in the cloud
Sugar
Petrol
Salt

Test your knowledge

1. The mixture is:

A. Distilled water

C. Aluminum

2. The following is not a mixture:

Distilled water
The soil

Test your knowledge

3.Indicate heterogeneous mixtures

A) granulated sugar + water

B) sulfur + iron filings

C) table salt + water

Test your knowledge

4. Specify homogeneous mixtures

B) river sand + water

C) oil + water

Test your knowledge

5. In what case we're talking about about water as a pure substance?

A) sea water tastes salty

B) distilled water is obtained by cooling water vapor

C) mineral water is used to treat certain diseases

Test your knowledge

6. Label the mixture whose main component is gas

A) oxygen

B) carbon dioxide

Explain from a chemical point of view:

“Meanwhile, the Needlewoman returns, strains the water, pours it into jugs; and what a trick: if the water is unclean, he will roll up a sheet of paper, put coals and coarse sand in it, insert that paper into a jug and pour water into it, and the water, you know, passes through the sand and through the coals and drips into the jug clean like crystal..."

(Odoevsky V.F. “Moroz Ivanovich”)

Homework:

§ 24, ex. 4,5,6,7

Creative task.

1. Create tasks for separating a mixture.

2. You were given a mixture consisting of salt and chalk. Suggest ways to separate this mixture.

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Slide captions:

Pure substances and mixtures. Physical phenomena in chemistry.

Substances that have constant physical properties are called pure.

A mixture is a combination of different substances that can be separated because they have different physical properties (for example, different boiling points). The substances in the mixture are not linked by chemical bonds, so they can be separated from each other.

Mixtures Homogeneous (homogeneous) Heterogeneous (heterogeneous) Solutions of table salt (sodium chloride) and sugar in water, air A mixture of table salt with sand, clay with water, iron filings with clay

Problem: How to obtain pure substances?

The production of pure substances was based on physical processes that occur without changing the composition of the substance, but with a change states of aggregation substances.

Heterogeneous mixtures Sedimentation Filtration Magnetic action Sedimentation of clay particles in water. Used for cleaning drinking water Used in drinking water purification Separation of iron from other substances

Homogeneous mixtures Evaporation Crystallization Distillation (distillation) Chromatography Isolation of table salt from sea water Sugar production Obtaining distilled water Separation and purification of medicinal substances

How to purify water while camping?

The following mixtures are given: - iron and copper filings; - sawdust and clay; - river sand and sugar. Suggest ways to separate them.

On the topic: methodological developments, presentations and notes

Lesson summary "Pure substances and mixtures. Methods for separating mixtures"

Lesson objectives:1. Educational: Give the concept of a pure substance and a mixture of substances, the similarities and differences between them. Reveal the meaning of mixtures in nature and human life.2. Educational: F...