The concept of evaporation The concept of boiling .

The concept of evaporation:

Definition 1: The process of phase change of matter from a liquid state to a gaseous state.

Definition 2: The process of phase change of water from a liquid or solid state to a gaseous state.

Definition 3: Vaporization that occurs on the surface of a liquid.

Definition 4: The process by which liquid water is converted into gaseous water and escapes into the atmosphere.

Definition 5: The process by which water vapor escapes from the surface of water, ice, or other aqueous substances when the temperature is below the boiling point.

Definition 6: The process of phase change of matter from a liquid state to a gaseous state.

The concept of boiling: the phenomenon of violent vaporization of a liquid inside and on the surface of the liquid at the same time when it is heated beyond its saturation temperature.

The connection between evaporation and boiling:

They are all ways of vaporization of liquids, that is, they are all vaporization phenomena, and liquids need to absorb heat in the process of evaporation and boiling.

Difference Between Evaporation and Boiling:

1) Evaporation is the vaporization of a liquid at any temperature (ignore, because it is absolute zero, at this time, the molecules stop moving), while boiling is the vaporization of the liquid at a certain temperature (boiling point) and continues to heat up.

2) Evaporation is a slow vaporization phenomenon that occurs only on the surface of a liquid, while boiling is a violent vaporization phenomenon that occurs both on the surface and inside the liquid.

3) The temperature of the liquid decreases during evaporation, while the temperature of the liquid remains the same during boiling (under the premise that the pressure on the surface of the liquid does not change).

4) The factors that affect the evaporation rate are: the surface area of the liquid, the temperature of the liquid, the air velocity near the surface of the liquid; The factors that affect the boiling point are: the air pressure on the surface of the liquid, how pure the liquid is. Factors that affect the rate of boiling: the volume of the liquid and the original temperature.

5) There are bubbles when boiling, and no bubbles are produced when evaporating.

6) The microscopic essence of evaporation is: due to the thermal movement of the molecules, the molecules on the surface of the liquid leave the liquid and enter the air. (7) Evaporation will take place at any temperature, but the higher the temperature, the faster, and vice versa. The boiling must be at the boiling point and continue to absorb heat.

The microscopic nature of boiling is that due to the violent vaporization of bubbles, not only the molecules on the surface of the liquid will leave the liquid, but also the molecules on the bubble wall inside the liquid will also leave the liquid and enter the air. The phenomenon of boiling includes the phenomenon of evaporation, but the phenomenon of evaporation does not include the phenomenon of boiling.

Evaporation: A slow vaporization of a liquid at any temperature on the surface of a liquid. Meteorologically, it refers to the process by which a liquid becomes a gas. In modern Chinese, it is often described as a person or object that is abnormally in a state of near disappearance.

Boiling: A phenomenon of intense vaporization that occurs simultaneously on the surface and inside the liquid.

When the liquid is heated, it will evaporate, because the liquid absorbs a large amount of hot gas, changes its molecular arrangement and structure, and causes it to become a gas, which is called evaporation, and it should be like this.

I guess, don't take it seriously.

Boiling, I think the same as above, is just too much liquid, and when it is released at the same time, the gas squeezes the liquid, and the liquid boils to be formed

The difference between evaporation and boiling is: different temperature conditions, different locations of occurrence, and different influencing factors.

First, the temperature conditions are different.

1. Evaporation: Evaporation is the vaporization of a liquid at any temperature.

2. Boiling: Boiling is the vaporization phenomenon that can only occur when a liquid is heated at a certain temperature (boiling point) and continues to be heated.

Second, the location of the occurrence is different.

1. Evaporation: Evaporation is a slow vaporization phenomenon that occurs only on the surface of a liquid.

2. Boiling: Boiling is a violent vaporization phenomenon that occurs simultaneously on the surface and inside of a liquid.

Third, the influencing factors are different.

1. Evaporation: the surface area of a liquid.

The temperature of the liquid, the velocity of the air near the surface of the liquid.

2. Boiling: the air pressure on the surface of the liquid, the purity of the liquid. Factors that affect the rate of boiling: the volume of the liquid and the original temperature.

Similarities: Evaporation and boiling are both vaporization phenomena and both need to absorb heat.

Differences: 1. Different locations of occurrence: evaporation is a vaporization phenomenon that occurs only on the surface of a liquid, while boiling is a violent vaporization phenomenon that occurs both inside and on the surface of a liquid.

2. Different temperature conditions: evaporation can occur at any temperature, while boiling occurs at a certain temperature.

3. The temperature change may be different: the liquid needs to absorb heat when it evaporates, and the temperature may decrease; During boiling, the heat is absorbed but the temperature remains the same.

4. Different degrees of intensity: evaporation is relatively gentle, while boiling is very violent.

5. Different influencing factors: the speed of evaporation, the temperature of the liquid, and the surface area.

The velocity of air flow on the surface is related to the boiling boiling point with atmospheric pressure.

is related to the height of the high.

Update 1:Write out two factors that affect the rate of evaporation.

Boiling and closing are similar to evaporation: both are the same as the change of matter from liquid to gaseous. Both are likewise endothermic processes.

Boiling is not the same as evaporation: the temperature at the time of boiling is the boiling point of the substance, whereas evaporation takes place at a temperature below the boiling point. There is effervescent when boiling, and there is no sock when evaporating.

Two factors affect the rate of evaporation: The higher the temperature, the faster the evaporation. The higher the humidity of the empty space, the slower the evaporation.

2009-02-03 00:50:37 Added:

The last sentence should be the humidity of the air .

Factors that affect evaporation are temperature, wetness, surface area of the liquid, velocity of air flow above the surface of the liquid, etc. The faster the temperature, the faster the evaporation. The main factors that affect the boiling of liquids are air pressure, temperature, and heat supplementation.

The main factors influencing evaporation:

1. It is related to the temperature. The higher the temperature, the faster the evaporation. No matter what the temperature is, there are always some molecules in the liquid with a high velocity that can fly out of the liquid surface and become vapor molecules, because Qingchang shouted that this liquid can evaporate at any temperature.

If the temperature of the liquid increases, the average kinetic energy of the molecules increases, and the number of molecules flying out of the liquid surface increases, so the higher the temperature of the liquid, the faster it evaporates.

2. It is related to the size of the liquid surface area. If the surface area of the liquid increases, the number of molecules in the vicinity of the surface of the liquid increases. Therefore, in the same time, the number of molecules flying out of the liquid surface increases, so the liquid surface area increases, and the evaporation accelerates.

3. It is related to air flow. When vapor molecules flying into the air collide with air molecules or other vapor molecules.

(1) Similarities: evaporation and boiling are both vaporization phenomena and endothermy. Process.

2) Differences:

a. Different forms of expression: evaporation is a vaporization phenomenon that only occurs on the surface of the liquid, while boiling is a vaporization phenomenon that occurs inside and on the surface of the liquid at the same time;

b. Different degrees of intensity: evaporation is a slow vaporization phenomenon, and boiling is a violent vaporization phenomenon;

c. Different temperature conditions: evaporation can occur at any temperature, while boiling occurs at the boiling point temperature;

d. Different temperature changes: when the liquid surface evaporates, it actually absorbs heat from the inside of the liquid, which can reduce the temperature of the liquid; However, although the liquid absorbs heat during the boiling process under a certain air pressure, it keeps the boiling point temperature unchanged.

e. Different endothermic methods: evaporation does not have to be heated naturally (liquid evaporation can absorb heat from inside the liquid), and the boiling process must continuously heat the liquid;

f. Different influencing factors: the speed of evaporation is related to the temperature, surface area, and air flow speed of the liquid, and the boiling point of boiling is related to the level of atmospheric pressure.

[Physical] [vaporization phenomenon - evaporation] - Analyze and understand evaporation and boiling.

Vaporization: The transformation of a substance from a liquid state to a gaseous state. (The vaporization process requires endothermy, and there are two forms: evaporation and boiling hood).

Evaporation: A vaporization phenomenon that occurs only on the surface of a liquid surface. (Liquids can evaporate under any circumstances, and evaporation has a refrigeration effect).

Factors influencing the speed of evaporation.

1.The higher the temperature of the liquid, the faster it evaporates.

2.The greater the surface area of the fluid, the faster the hair increases.

3.The faster the air flow on the surface of the liquid, the faster it evaporates.

Boiling: At the same temperature (boiling point), a vigorous vaporization process is carried out simultaneously on the surface of the liquid and inside the substance stuffing liquid. (Boiling requires endothermy).

Boiling Point: The temperature at which a liquid boils. (The boiling point has a certain relationship with the pressure, the pressure is high and the boiling is high, and the pressure is low and the boiling is low.) The boiling point of water under standard pressure is 100).

Boiling conditions.

The temperature reaches the boiling point and continues to absorb heat.

Liquefaction: The process by which a substance changes from a gaseous state to a liquid state. (Liquefaction requires exothermy).

The way of liquefaction.

1.Reducing the temperature, all gases can be liquefied to a certain degree of dust when the temperature is lowered.

Such as: dew, fog, etc.

2.Compression volume, some gases can be liquefied by compressing volume alone.

Such as: liquefied petroleum gas, liquid lighters, etc.