Class notes on the state of matter and its changes, and a detailed summary of the knowledge of the c

1. Vaporization and liquefaction.

Vaporization: Key points Explanation: The change of substance from liquid to gaseous state is called vaporization; There are two different ways of vaporization: evaporation and boiling, both of which are endothermic. Evaporation:

1) Evaporation is a relatively slow vaporization of a liquid that occurs at any temperature and only occurs on the surface of the liquid.

2) Factors affecting the speed of evaporation: the temperature of the liquid, the size of the surface area of the liquid, and the speed of air flow on the surface of the liquid.

3) Liquid evaporation and heat absorption, which has a cooling effect.

Boiling: 1) Boiling is a violent vaporization phenomenon that occurs simultaneously inside and on the surface of a liquid at a certain temperature.

2) Conditions for liquid boiling: The temperature reaches the boiling point; Continue to absorb heat.

Boiling point: The temperature at which a liquid boils.

Phenomenon when water boils: Violent vaporization, a large number of vertical bubbles rise, become larger, and burst to the surface of the water, and the water vapor inside is emitted into the air. Although it continues to be heated, its temperature remains the same.

Liquefaction: Key points Explained: The phenomenon of a substance changing from a gaseous state to a liquid state. Liquefaction and exothermy.

The method of liquefiing the land car: 1. Reduce the temperature (all gases can be liquefied). 2. Compress the volume.

Benefits of liquefaction: Reduced volume, easy storage and transport.

Note: Vaporization and liquefaction are inverse processes to each other, vaporization is endothermic and liquefaction is exothermic.

2. Sublimation and condensation.

Key points interpretation: sublimation and endothermy, condensation and exothermy, are mutually inverse processes.

Sublimation: The direct change of matter from a solid state to a gaseous state is called sublimation.

Example: Frozen clothes dry in winter, filaments become thinner, and sanitary balls become smaller.

Sublimation; The phenomenon of matter directly changing from a gaseous state to a solid state.

Examples: frost, tree hangings, window flowers.

Regular method guidance:

1. The difference and connection between evaporation and boiling:

Similarities Differences.

The location of the temperature requirement degree affects the condition.

Evaporation and vaporization are all evaporation.

All need to absorb heat Surface No special requirements Slow Surface temperature, surface air flow velocity, surface area size.

Boiling inside and on the surface must reach the boiling point violently The boiling point is affected by atmospheric pressure.

2. The changes of endothermic state are: melting, vaporization, and sublimation; Exothermic are: coagulation, liquefaction, and condensation

Dialysis of classic example questions:

Examination of knowledge of vaporization and liquefaction.

1. The wet and dry bulb thermometer is made of two identical thermometers in parallel, when in use, the glass bubble at the lower end of the right thermometer in the figure is wrapped with a wet cloth, because the water should be evaporated when the reading of the right thermometer is higher than the reading of the left thermometer Because the less the content of water vapor in the air, the faster the water will evaporate, so that the difference between the thermometer of the dry bubble and the wet bubble is large, which indicates the water vapor content in the air

Melting, steam spoiling, spikeping, evaporation, ascending, Linghua - endothermic cooling.

Evaporation:Coagulation Liquefaction (there are two ways to compress the volume and cool down) Condensation -- Heat up with dry heat.

Chapter 2 Changes in the state of matter.

The tri-state temperature of a substance is measured.

Vaporization and liquefaction.

Melt and solidify.

Sublimation and condensation.

Thermal phenomena of water circulation.

1. Temperature: The degree of heat and cold of the object is called temperature 2. Celsius temperature (symbol: t unit:

Celsius< > Sweden's Resiaught stipulated: The temperature of the pure ice-water mixture is set to 0 The temperature of pure water boiling at 1 standard atmosphere is specified as 100 Divide between 0 and 100 into 100 equal parts, and each equal part is a 3. Thermometer principle: the structure made of the properties of thermal expansion and contraction of liquids

Glass shell, capillary, glass bubble, scale and liquid use: Before using the thermometer, pay attention to the observation range and recognize the division value, and use the thermometer to measure the temperature of the liquid to do the following three things: The glass bubble of the thermometer should be fully immersed in the measured object; Wait for the indication to stabilize before reading; When reading, do not take out the thermometer from the liquid, and the line of sight should be level with the surface of the liquid surface, 4. The main difference between the thermometer, the experimental thermometer, and the cold and summer table Construct the range Graduation value Usage thermometer There is a notch above the glass bubble 35-42 Leave the human body reading, and shake the experimental thermometer before use None -20-100 1 You can't leave the reading of the analyte, and you can't shake off the cold and summer table None -30 -50 1 Ibid.5 Melting and solidifying substances from solid to liquid are called melting, and melting endothermic substances from liquid to solid state are called solidification, Solidification should be exothermic 6, melting point and freezing point, solid splitting crystalline and amorphous two types of melting point:

Crystals have a certain melting temperature, which is called the melting point; Amorphous has no melting point and freezing point: crystals have a certain freezing temperature, which is called freezing point; Amorphous has no freezing pointThe freezing point of the same substance is the same as its melting pointConditions for crystal melting: Reaching the melting point temperature Conditions for continuing to solidify the liquid from the outside into crystals:

Reach the freezing point temperature Continue to release heat to the outside Memory Some common crystals and amorphous 7, vaporization and liquefaction of substances from liquid to gaseous state is called vaporization, and vaporization has two different ways: evaporation and boiling, both of which are endothermic. The change of a substance from a gaseous state to a liquid state is called liquefaction, and liquefaction has two different ways:

Reducing the temperature and compressing the volume, both of which require exothermy. 8. Definition of evaporation phenomenon: evaporation is a factor that can occur at any temperature of liquid, and the vaporization phenomenon that only occurs on the surface of the liquid affects the speed of evaporation

The temperature of the liquid, the size of the surface area of the liquid, the speed of the air flow on the surface of the liquid9, the definition of the boiling phenomenon: boiling is the violent vaporization phenomenon that occurs in the liquid at a certain temperature, both inside and on the surface at the same time, the conditions for liquid boiling: The temperature reaches the boiling point and continues to absorb heat10, the sublimation and condensation of substances from the solid state directly to the gaseous state is called sublimation, and the direct change from the gaseous state to the solid state is called the sublimation and condensation phenomenon in daily life (frozen wet clothes dry out, frost is seen in winter).

1.Melting:Definition:

The change of an object from a solid state to a liquid state is called melting Features: Crystal melting: solid-liquid coexistence, heat absorption, and constant temperature.

Amorphous melting: endothermy, first softens and thins, and finally becomes liquid, and the temperature rises. Melting conditions:

1.Melting point is reached. 2。

Continue to endothermy2Coagulation: Definition:

The change of matter from liquid to solid state is called solidification Characteristics: Crystal: solid-liquid coexistence, exothermic, and the temperature remains unchanged.

Amorphous: exothermic, gradually thickening, becoming viscous, hardening, and finally solid, the temperature continues to decrease Solidification conditions: 1

Freezing point reached. 2.Continue to exothermic 3

Gasification: Definition: The change of a substance from a liquid state to a gaseous state is called vaporization Evaporation:

Definition: The gasification of a liquid at any temperature and only on the surface of the liquid is called evaporation. Influencing factors:

1.Liquid temperature. 2.

The surface area of the liquid. 3。Flow of air on the surface of a liquid Action:

Evaporative endothermy, with refrigeration boiling : Definition: The phenomenon of violent vaporization that occurs simultaneously inside and on the surface of a liquid at a certain temperature.

Boiling Point: The temperature at which the liquid boils Boiling conditions: 1

Reaches the boiling point. 2.Continue the relationship between endothermic boiling point and air pressure; The boiling point of all liquids is that the air pressure decreases when it decreases and rises when the air pressure increases.

Liquefaction: Definition: The change of a substance from a gaseous state to a liquid state is called the liquefaction method:

1.Reduce the temperature. 2.

Compression volume effect: liquefaction, exothermic sublimation and condensation: sublimation definition:

The process of a substance directly changing from a solid state to a gaseous state, endothermic and sublimation substances are: iodine, ice, dry ice, camphor, tungsten condensation Definition: The process of a substance directly changing from a gaseous state to a solid state, exothermic.

1.Melting: Definition: The change of an object from a solid state to a liquid state is called melting.

Features: Crystal melting: solid-liquid coexistence, endothermy, constant temperature.

Amorphous melting: endothermy, first softens and thins, and finally becomes liquid traces and states with rising temperatures. Melting conditions:

1.Melting point is reached. 2。

Continue to endothermy2Coagulation: Definition:

The change of a substance from a liquid state to a solid state is called solidification.

Features: Crystal: solid-liquid coexistence, exothermic, constant temperature. Amorphous: Exothermic, gradually thickening, becoming viscous, hardening, and finally solid, with a constant decrease in temperature.

Coagulation conditions:1Freezing point reached. 2.Continue to exothermic 3Gasification: Definition: The change of a substance from a liquid state to a gaseous state is called gasification.

Evaporation: Definition: The vaporization of a liquid at any temperature and only on the surface of the liquid is called evaporation.

Influencing factors:1Liquid temperature.

2.The surface area of the liquid. 3。

The flow of air on the surface of a liquid.

Function: Evaporation and endothermy, with refrigeration Boiling: Definition:

At a certain temperature, the phenomenon of violent vaporization occurs simultaneously inside and on the surface of a liquid. Boiling Point: The temperature at which the liquid boils Boiling conditions:

1.Reaches the boiling point. 2.

Continue the relationship between endothermic boiling point and air pressure; The boiling point of a liquid decreases when the air pressure decreases and increases when the air pressure increases. Liquefaction:Definition:

The change of a substance from a gaseous state to a liquid state is called the liquefaction method:1Reduce the temperature.

2.Compression volume effect: liquefaction, exothermic sublimation and condensation:

Definition of sublimation: the process of matter directly changing from solid to gaseous, endothermic and easy to sublimate substances are: iodine, ice, dry ice, camphor, tungsten condensation definition:

The process by which a substance changes directly from a gaseous state to a solid state, exothermic. The above are a few of the changes in the state of matter. If satisfied.