"Changes of Water Molecules" Exploring the Water World PPT

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"Changes of Water Molecules" Exploring the Water World PPT, 18 pages in total.

1. Introduction of new courses

One day in 1973, a fire broke out in the waters of a bay in Madras, southeastern India. At that time, the sea had been stormy for several days. On this day, after a powerful hurricane, a raging fire suddenly ignited on the sea surface. It was quite spectacular, and the fire illuminated dozens of kilometers in all directions. The raging fire, the fierce flames actually connected the sea and the sky, forming a spectacular and wonderful scene with half the wall red, and all the witnesses were stunned.

Why does seawater catch fire? This is closely related to the composition of water. In this lesson we will learn about the composition of water.

2. Decomposition of water

[Experimental Investigation 2-2] Changes in water under the action of direct current

1. Fill the glass tube of the water electrolyzer with water and connect the DC power supply. Observe the changes in the liquid level in the two electrodes and the two glass tubes?

There are bubbles emerging from the electrode carbon rod, the water surface in the glass tubes on both sides drops, and the water surface in the middle glass tube rises. The volume of air in the positive glass tube: the volume of air in the negative glass tube = 1:2

2. Use a lit match to approach the tip of the glass tube where the liquid level has dropped more, slowly open the piston, and observe the phenomenon.

The gas in the tube is ignited at the mouth of the tube, and the flame appears light blue.

3. Use a wooden stick with sparks to approach the tip of the glass tube where the liquid level drops less, slowly open the piston, and observe the phenomenon.

Sparkling wood sticks rekindled.

3. Synthesis of water

1. Physical properties of hydrogen

Physical properties of hydrogen: Hydrogen is a colorless, odorless, insoluble gas with a density smaller than that of air.

What fuel does the space shuttle use to launch?

The space shuttle uses liquid hydrogen as fuel for launch, indicating that hydrogen is flammable, so let's study hydrogen combustion now.

2.Purity test method

How does the purity test work?

4. Classroom exercises

1. In winter, water pipes carrying water are easy to freeze and crack. The main reason is ()

A. Iron pipes expand and contract with heat and cold

B. Iron pipe heat shrinks and cold expands

C. Liquid water is denser than ice

D. Ice is denser than liquid water

2. Water is decomposed into hydrogen and oxygen under the action of direct current. Explain ()

A. Water is composed of hydrogen and oxygen

B. Water is composed of hydrogen and oxygen elements

C. There are hydrogen and oxygen in water

D. Mix hydrogen and oxygen thoroughly to get water.

5. Class Summary

1. Common methods for water purification

1. Standing precipitation method: simply remove insoluble impurities in water.

2. Adsorption precipitation method: remove suspended solids and insoluble impurities in water.

3. Filtration method: It is better to remove insoluble impurities in water.

4. Distillation method: remove soluble impurities in water.

2. Hard water and soft water

1.Definition:

Hard water - Water that contains more soluble calcium and magnesium compounds.

Soft water - Water that contains no or less soluble calcium and magnesium compounds.

2. Differentiation methods: soap water method and evaporation method.

3. Hard water softening methods: boiling, distillation, etc.

Keywords: Free download of Chemistry PPT courseware for the first volume of the ninth grade of the Lujiao Education Edition, PPT download of changes in water molecules, PPT download of Exploring the World of Water, .PPT format;

For more information about the PPT courseware "Exploring the Changes of Water Molecules in the Water World", please click the "Exploring the Changes of Water Molecules in the Water World" PPT tab.

"Changes of Water Molecules" Exploring the Water World PPT courseware:

"Changes of Water Molecules" Exploring the Water World PPT courseware, 18 pages in total. Wen Jiu Zhi 1. Describe the microscopic composition of water? 2. Describe the process of water disappearing from your hands from a microscopic perspective. 3. Is it possible that the water molecules in this drop of water will appear in front of you again one day in the future?

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Update Time: 2024-10-16

This template belongs to Chemistry courseware Lu Jiao Edition Ninth Grade Chemistry Volume 1 industry PPT template

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