Why does water get hot, and what changes in the process of water getting hot

Because the water pipe near the faucet is generally exposed, and the water pipe behind it is buried in the ground. When few people use it, they use water from the exposed water pipe in front of it, so it is very cold. When many people use it, the water in the front section of the water pipe is quickly used up, and the water in the water pipe buried in the ground is hot.

The constant flow of water will increase its internal energy, which is not very hot, but at least it is not as cold as when few people use it

Because the water pipe has a certain length.

When the water has been placed.

The cool water in the water pipe was drained.

Hot water came out.

It's winter, maybe it's because your school burns boilers, and you think that when there are more people, you burn more coal, and when there are fewer people, you burn less, so the water will be icy.

If the hot water pipe is not used for a long time, the hot water in it will be cold, and the cold water needs to be drained to have hot water. This kind of problem will not occur if someone uses it often.

If you cook it, it will be hot...

If the hot water pipe is not used for a long time, the hot water will be cold and cold.

When the water flow rate increases, a certain heat energy temperature is generated, and vice versa, when the water flow rate decreases, the water temperature is lower.

The water in my school is hot when many people use it! It's very icy if few people use it! Why is that?

Because if there is a temperature difference between the water and the external object, then the internal energy will be transferred.

If the temperature of the external object is higher than that of water, the internal energy of the object will be transferred to the water, and the water will absorb heat and heat up.

1. When the overall temperature of water (liquid) reaches its boiling point and continues to be heated, the liquid can be vaporized at the same time due to heat absorption, that is, at this time, not only the liquid surface liquid is transformed into a gaseous state, but also the gaseous bubbles escape from the liquid inside, which is "boiling";

2. Observe the bottom of the heated water tube, the bottom water first reaches the boiling point due to its proximity to the heat source, and the bubbles rise in the water after the bottom water vaporizes, but the water temperature of the upper layer has not yet reached the boiling point, and the water vapor in the bubbles in the rising process re-condenses into water due to the temperature drop, and the volume of the bubbles decreases; When the water temperature in the test tube reaches the boiling point, the rising bubbles increase in volume due to the continuous addition of vaporized water vapor, the bubbles become larger, and the water is opened;

3. When the inside of the liquid is heated to the boiling point, and the volume of the vaporized bubbles inside the liquid increases during the rise of the liquid inside, it is called "boiling".

Evaporation and boiling.

Both are vaporization phenomena, and they are two different ways of vaporization. Evaporation is the process of vaporization that occurs on the surface of a liquid, and boiling is a violent vaporization phenomenon that occurs both inside and on the surface of a liquid [2]. Evaporation of a solution usually refers to the process of vaporizing a part of the solvent in the solution by heating to increase the concentration of non-volatile components in the solution (concentration) or to precipitate the solute from the solution and crystallize.

In general, the higher the temperature, the larger the exposed area of the liquid level, and the faster the evaporation rate. The lower the pressure on the surface of the solution, the faster the evaporation rate.

I've never found water heating to produce such a magical effect!

1. The volume has changed, but the weight has not. As the temperature of the water increases, the volume of water becomes larger and larger. appliedThermal expansion and cold contractionThe hotter the surrounding environment, the larger the object will expand; Conversely, the colder the surrounding environment, the smaller the object will shrink.

2. The density of water has changed, the higher the water temperature, the lower the density of water. When the density of the water decreases, the objects in the water will sink.

Comparison before and after boiling:

Bubbles are produced when boiling. In fact, bubbles are formed in the liquid when heated to a certain temperature (non-boiling point) before boiling. The bubbles in the liquid before boiling are not the vapors after the liquid has vaporized, but the air that was originally dissolved in the liquid.

Because the higher the temperature, the weaker the dissolution ability of the gas in the liquid, so that some of the air originally dissolved in the liquid cannot be dissolved after heating, and the liquid overflows.

The bubbles before boiling, the more they reach the liquid, the smaller they become. The reason is that when the liquid is heated, the temperature of the upper layer of the liquid is lower than that of the lower layer, and the solubility of the upper layer of the liquid is stronger than that of the lower layer. In the bubble, some of the gases that cannot be dissolved in the liquid in the lower layer float to the lower temperature of the upper layer, and dissolve in the liquid again, making the bubble smaller.

Most of the bubbles produced before boiling have become smaller and disappear before reaching the surface of the liquid.

The bubble during boiling is the vapor after the liquid has vaporized, and this bubble becomes larger the higher it reaches the upper layer of the liquid. This is because the bubbles in the lower layer are mixed with other bubbles as they float up, making the bubbles bigger and bigger. The bubbles produced during boiling will burst when they reach the surface of the liquid.

After rupture, it forms water vapor with the surrounding boiling water.

After leaving, it is liquefied into small water droplets, which are the "white gas" we see.

Water heating or as the temperature rises can turn into water vapor and fly into the air, and water vapor in the air can turn into fog, dewdrops, rain, snow, hail, etc. If the temperature is too low, the water can freeze directly. Water can also be turned into hydrogen and oxygen, among other things.

Water is a colorless, tasteless, and odorless liquid at room temperature. Many common gases can be dissolved in water, such as hydrogen, oxygen, nitrogen, carbon dioxide, inert gases, etc., and the solubility of these gases is related to factors such as temperature, pressure, and partial pressure of the gas phase.

When the water is heated and the temperature is not higher than the boiling point of the local water, evaporation will occur and it will become water vapor (there is still water at this time); When the temperature is higher than the boiling point, boiling occurs, which also becomes water vapor.

The weather is getting hotter and hotter, and many people take a hot bath every day. There are many customers who use gas water heaters at home, and when they use them, they suddenly find that the water heater at home is a little abnormal, and the temperature is getting higher and higher. Is this abnormal?

The first reason is natural factors.

It can be seen that the temperature is getting higher and higher, and it is early to enter the summer. Especially in the summer, when many objects are exposed to the sun, the temperature of the tap water pipe can even reach more than 60 degrees, and the internal temperature of the tap water can even reach more than 40 degrees. If you look at it this way, it is obvious that external factors cause the water temperature of the water heater to become hot.

Because the average temperature of the human body is 37 degrees, and the comfortable temperature is about 40 degrees. If the temperature of tap water has reached 40 degrees, and it is heated by a gas water heater, it must be an unacceptable temperature for the human body. That's why people think the water is hot.

The second reason is the product factor.

If the water pressure in your home is too low, the outlet is blocked, the water temperature is too low or too high, and the water temperature does not meet the conditions of the water, the water temperature will become hot.

If the water pressure is too low and the water outlet is blocked, it will affect the normal ignition of the gas water heater or cause the water temperature to be too high! If the water pressure problem is to change the water pipe to a certain caliber or install a booster pump;

The blockage of the water outlet can be solved by cleaning the filter screen of the water heater outlet pipe, replacing the shower, or contacting the after-sales door-to-door cleaning service of professional manufacturers! The simplest verification method, the same time, heating half a pot of water and heating a full pot of water, half a pot of water water temperature must be a full pot of water.

The gas pressure is too high.

In general, the high gas pressure is mainly reflected in the liquefied gas (LPG), and the pressure reducing valve of the liquefied gas (it is recommended to use the labor brand is recommended) to adjust the gas pressure to the required value to reduce the water temperature.

The simplest verification method, the same time, heating the same water, the flame is adjusted to different gears, the higher heating gear, the boiling time will be earlier than the lower gear.

If these two methods are ruled out, and your water heater is scalding and unusable, it is recommended that you really find someone to repair it quickly, and don't burn yourself and your family.

It also turns into ice and water vapor.

If you heat the small water droplets, the small water droplets will boil and quickly turn into water vapor. When the water vapor is cold, it will condense into small water droplets. If the water droplets are cooled to a low temperature of 0 degrees Celsius, the water droplets will condense into solid ice cubes.

When the ice is heated, it melts into small liquid droplets.

Water absorbs heat and vaporizes into water vapor; Water vapor emits heat, which is condensed into ice or liquefied into water, respectively. Ice absorbs heat and melts into water; Water is exothermic and solidifies into ice; Ice absorbs heat and melts into water.

Water can turn into water vapor when heated or as the temperature increases.

Flying into the air, the water vapor in the air can turn into fog, dewdrops, rain, snow, hail.

Wait. If the temperature is too low, the water can freeze directly. Water can also be turned into hydrogen and oxygen, among other things.

Water is a colorless, tasteless, and odorless liquid at room temperature. Many common gases can be dissolved in water, such as hydrogen, oxygen, nitrogen, and carbon dioxide.

Inert gases, etc., the solubility of these gases.

It is related to factors such as temperature, pressure, partial pressure of the gas phase, etc.