"Several Common Salts" Salt PPT Courseware

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"Several Common Salts" Salt PPT Courseware

1. Sodium chloride (the main component of table salt)

1. Physical properties: white crystal, easily soluble in water (its solubility does not change much with temperature).

2. Preparation method: Generally, the solvent evaporation method is used.

3. Uses: kitchen condiments; medical preparation of physiological saline; agricultural use of sodium chloride solution for seed selection; industrial use for the production of chlorine and caustic soda; transportation use for clearing snow on roads.

4. Note: Industrial salt contains sodium nitrite (NaNO2), which looks similar to table salt and is toxic and easily carcinogenic. Pay attention to the distinction.

2. Sodium carbonate (Na2CO3)

1) Preparation method

(1) Alkali lake fishing method

(2) Hou's combined alkali production method

In 1921, Hou Debang, who studied in the United States, resolutely returned to China. After several years of painstaking research, he finally figured out the full set of Solvay process technology used in the production of soda ash in the United Kingdom, allowing my country to also produce soda ash using chemical methods. He continued to explore in the future. A new method of making alkali was successfully studied in 1940 and was later named "Hou's combined alkali making method".

1. Physical properties of sodium carbonate and sodium bicarbonate

2. Chemical properties of sodium carbonate and sodium bicarbonate

Experimental study one

① Comparison of the acidity and alkalinity of sodium carbonate and sodium bicarbonate

Experimental exploration two

②Comparison of the reactions of sodium carbonate and sodium bicarbonate with hydrochloric acid

Let's do a simple experiment: P56

1. Take a small piece of flaky limestone (or shell, eggshell) and observe it carefully to see if it is easy to crush or break.

2. Use crucible pliers to hold the limestone, place it in the outer flame of an alcohol lamp or gas lamp and burn it for a few minutes, then place it in an asbestos net to cool and see if it is easy to crush or break.

3. Burn another piece of limestone for a few minutes, then put it into a small beaker filled with cold water. What phenomena can be seen?

After letting it stand, take out a small amount of the upper clear liquid and place it in two test tubes. Add 2 drops of phenolphthalein test solution to one test tube, blow air into the liquid in the other test tube, and observe the phenomenon.

4. Record the results you observed, try to explain them with knowledge of chemistry and physics, and communicate with your classmates.

1) When materials containing calcium carbonate are burned at high temperatures, the calcium carbonate in them will be converted into loose calcium oxide and carbon dioxide.

The above process can be briefly expressed as follows:

CaCO3==CaO+CO2↑

2) Calcium oxide: commonly known as quicklime

1. Properties: white solid; reacts with water

CaO +H2O==Ca(OH)2 exothermic

Quick lime Hydrated lime

2.Usage:

① Use as food desiccant: strong water absorption

②Building materials

3) Calcium hydroxide: commonly known as slaked lime, slaked lime

1. Properties: White solid, slightly soluble in water, the resulting solution is clear lime water. The slurry formed is lime slurry.

2. Usage: building materials (the principle is represented by chemical equations), improving acidic soil, and preparing pesticide Bordeaux mixture.

Ca(OH)2+CO2==CaCO3↓+H2O

Summary and summary

1. Limestone, quicklime and hydrated lime can be converted into each other. Please use chemical equations to express the three chemical reactions in the figure below.

(1)CaCO3 = CaO+CO2

(2)CaO+H2O = Ca(OH)2

(3)Ca(OH)2+CO2=CaCO3↓+H2O

Thinking, can you use chemical knowledge to explain the poem "Song of Lime"?

lime chant

Yu Qian

Thousands of hammers were used to carve out the mountains, → the limestone is hard in texture

The fire burns as if it were idle. →CaCO3 = CaO +CO2

Don’t be afraid of being shattered into pieces, →CaO+H2O = Ca(OH)2

To remain innocent in this world. →Ca(OH)2 + CO2 = CaCO3+H2O

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"Several Common Salts" Salt PPT Courseware 3:

"Several Common Salts" Salt PPT Courseware 3 Knowledge Review Knowledge Point 1 Sodium Chloride 1. Sodium chloride is _________ crystal, ____ is soluble in water, has a salty taste, melting point is 801℃, boiling point is 1413℃, The solution is ____ and is the main component of _____. 2.Sodium chloride occurs naturally..

"Several Common Salts" Salt PPT Courseware 2:

"Several Common Salts" Salt PPT Courseware 2 Salt is the product of the neutralization of acid and alkali. It is formed by combining the acid anion in the acid and the metal cation in the base. Thinking: Is the salt we are talking about now the table salt we usually eat? It is not that salt is a class of substances that includes...

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Update Time: 2024-09-09

This template belongs to Chemistry courseware Beijing Curriculum Reform Edition Ninth Grade Chemistry Volume 2 industry PPT template

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