"Classification of Elements and Matter" PPT courseware of elements and the world of matter (an important mixture in Lesson 2 - colloid)

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"Classification of Elements and Matter" PPT courseware of elements and the world of matter (an important mixture in Lesson 2 - colloid)

Part One: Introduction of New Course

[Discussion and exploration] Understanding liquids in life:

1. Water 2. Alcohol 3. Sulfuric acid 4. Dilute sulfuric acid 5. Sea water 6. Chlorine water

7. Salt water 8. Mud water 9. Oil water

1, 2, and 3 are pure substances; 4---9 are mixtures.

7 is solution; 8 is suspension; 9 is emulsion.

Classification of elements and substances PPT, part 2: knowledge sorting

1. Dispersion system

1. Dispersoid: a substance dispersed into particles.

2. Dispersant: The dispersant is dispersed into another substance. This substance (another substance) is called a dispersant.

3. Dispersion system: The mixture composed of dispersoid and dispersant is collectively called dispersion system.

4. Several common dispersion systems

Colloid: A dispersion system in which the diameter of dispersed particles ranges from 1 to 100 nm.

5. Comparison of three dispersions

2. Colloid

1. Purification and refining of colloids - dialysis

The method of using a semipermeable membrane to separate impurity molecules or ions in a colloid and purify and refine the colloid is called dialysis.

Principle: Colloidal particles cannot pass through the semipermeable membrane, but molecules and ions in the solution can pass through the semipermeable membrane.

2. Classification of colloids

Classification according to dispersant status

Aerosols: smoke, clouds, fog

Liquid sol: Fe(OH)3 colloid, AgI colloid

Solid solution: colored glass, smoky quartz

3. Properties of colloids

(1) Tyndall phenomenon

Definition: When a visible light beam passes through a colloid, a bright "light path" can be observed on the side of the incident light.

Reason: It is formed by the scattering of visible light by dispersed particles in the colloid.

Application: Distinguish between solutions and colloids.

(2) Electrophoresis

Under the action of direct current, the dispersed particles in the colloid move directionally.

Application: Utilize the effect of high-voltage electricity on gas dust (aerosol) to reduce air pollution.

(3) Coagulation - suitable for liquid sol

The dispersions are aggregated into larger particles, which precipitate under the influence of gravity.

Methods that can cause colloids to agglomerate:

a. Add soluble salt or acid or alkali

b. Add colloids with opposite charges

c. Heating or stirring

4. Preparation of colloids

(1) Preparation process of Fe(OH)3 colloid:

Take a small amount of distilled water in a beaker, heat it to boiling with an alcohol lamp, add saturated FeCl3 solution drop by drop into the beaker, and heat until the liquid turns transparent reddish brown.

(2) Precautions: Do not stir, and the heating time cannot be too long.

(3) Chemical equation: FeCl3 + 3H2O ==== Fe(OH)3 (colloid) + 3HCl

5. Uses of colloids

(1) Salt-braised tofu;

(2) Preparation and separation of soap;

(3) Alum water purification;

(4) FeCl3 solution is used to stop bleeding from wounds;

(5) Cement hardening;

(6) A large amount of smoke and dust in metallurgical plants is removed with high-voltage electricity;

(7) The adsorption and exchange process of ions in soil colloids and the role of fertilizer conservation.

Classification of elements and substances PPT, part 3: In-person testing

1. The essential difference between solution, turbid liquid and colloid is ( )

A. Transparency B. Dispersion particle size

C. Stability D. Tyndall phenomenon

2. The best way to identify colloids and solutions ( )

A. Smell B. Observe

C. Dilution D. Tyndall phenomenon

3. The common property of ferric chloride solution and ferric hydroxide colloid is ( )

A. The diameter of the dispersion is between 1nm and 100nm.

B. Permeable to filter paper

C. All have Tyndall effect

D. All are reddish brown

4. Which of the following statements about colloids is incorrect ( )

A. Tyndall phenomenon can be used to distinguish colloids and solutions

B. According to whether the dispersion system has Tyndall effect, the dispersion system is divided into solution, colloid and turbid liquid.

C. The main properties of colloids include Tyndall phenomenon, electrophoresis and coagulation.

D. The fundamental difference between solution, colloid and turbid liquid is the diameter of the dispersed particles.

5. The phenomenon that cannot be explained by the knowledge of colloids is ( )

A. Add gypsum to soy milk to make tofu

B. A pen using different brands of ink is prone to clogging.

C. Add NaOH solution to FeCl3 solution, and a reddish-brown precipitate will appear.

D. At the junction of sea water and river water, deltas are easily formed

Keywords: Free download of the PPT courseware for the compulsory course 1 of high school chemistry in Lu Ke version, PPT download of the classification of elements and substances, PPT download of the world of elements and matter, PPT download of an important mixture of colloids, .PPT format;

For more information about the PPT courseware "Elements and the Material World, Classification of Elements and Substances, An Important Mixture of Colloids", please click the "Elements and Material World ppt, Classification of Elements and Substances ppt, An Important Mixture of Colloids" ppt tag.

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Update Time: 2024-06-21

This template belongs to Chemistry courseware Lu Ke Edition High School Chemistry Compulsory Course 1 industry PPT template

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