The problem of boiling water, when boiling water, how to determine that the water has been boiled?

Drinking water is an important part of replenishing the body's energy in daily life, how should we tell that the water is boiling when we boil it? In fact, we will find that boiling water has certain characteristics, when the boiling water boils, it will make a gurgling sound, and it will bubble, and now there are generally electric kettles in everyone's lives, when we use electric kettles, we should also pay attention to safety to prevent being burned, so when choosing an electric kettle, we must choose a safe and reliable electric kettle. <>

1.When the water boils, the water is already boiling. In fact, water has a boiling point, when the boiling water is boiled to 100, the water will boil, and we must have observed such a phenomenon when boiling water, that is, the water will bubble, and it will make a loud noise, generally speaking, we can hear such a sound when we boil the water in the current household electric kettle, so we must ensure our safety when boiling water, to prevent being scalded by the boiling water, so the method of judging boiling water is also very simple.

2.Stay safe. We will find that in family life, if some children are more naughty, they may accidentally touch the outer wall of the kettle, so it is very likely to be burned, or due to an inadvertent act in daily life, it is likely to cause a great risk, so it is best for us to put the electric kettle out of reach of children, and at the same time, it is best to stay away from the electric kettle when we boil water, to ensure the safety of electricity and water, and to prevent ourselves from being burned and scalded.

3.Choose a safe and reliable electric kettle. Sometimes the danger often happens around us, for example, some cases of electric kettle**, it is obvious that the safety of electricity can not be ignored, so it is more important for us to choose a reliable electric kettle, generally speaking, it is safer to choose an electric kettle with brand protection.

If there are very large bubbles on the surface of the water and a lot of hot air is coming out, then the water is boiling.

After there is no sound, it means that the water has been boiled, and the water will be bubbling all the time, and the water inside will start to boil, and a large amount of water vapor will come out, which means that the water is boiling.

When the water is boiling, the sound is very loud, and there will be bubbles in the middle of the water, which means that the water is boiling, if the sound is particularly small and there are no bubbles, it means that the water is not boiling.

Under normal circumstances, if the temperature is particularly high, and there will be a very violent sound in the process of boiling water, and the white gas coming out is relatively large, this is boiling.

When the water boils, it means that the water has boiled, that is, when the boiling water boils to 100, the water will boil.

1. Open the lid when it is fast open.

When the water boils to 80 -90, the lid should be opened. Because the organic pollutants in the water are volatile, most of the harmful substances can be volatilized by opening the lid of the kettle.

2. Wait 3 minutes before turning off the heat.

Tap water is basically chlorinated, which will form halogenated hydrocarbons, chloroform and other compounds that affect human health. After the water is boiled to 100, the content of halogenated hydrocarbons and chloroform begins to decrease, continue to boil the water for 3 minutes to reach the safe drinking water standard, and then turn off the heat. However, it should be noted that boiling water is not always better the longer it boils!

3. Water should not be boiled repeatedly to drink.

The ideal drinking water is fresh water, and water that has been left out for too long is prone to microbial contamination, so it is best to drink it freshly boiled. And try not to boil the water repeatedly, so that the pure water will evaporate, so that the concentration of other harmful substances in the water that are not easy to volatilize will increase, so try not to drink.

Water is heated to a boiling point and boiled. 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.

Boiling water can be boiled again. Sometimes when the boiling water is finished, it will be cold when you forget to bottle it, and when you remember it, you will reheat it and put it in the bottle.

We usually say that we can't drink "thousand boiling water", not to say the water that is boiled again, but the water that has been boiled many times, the water will vaporize part of it when it is boiled, and repeated boiling will lead to a large number of mineral components remaining in the remaining water, the concentration is very high, and after drinking, it will increase the risk of liver, kidney, stomach, and intestinal stones, and the mineral concentration in the water boiled twice cannot reach the pathogenic concentration at all, and it can be drunk.

Usually said that you can't drink boiled water, it should be said that overnight water or long-term storage of boiling water boiled again, boiled water is the same as other food, should not be stored for a long time, overnight boiling water will have a certain concentration of nitrite, this ingredient is a carcinogen, although the concentration is not high, but long-term drinking will gradually be enriched, so that it causes disease.

What water in life can not be drunk.

Raw water contains a variety of microorganisms and viruses, which cannot be directly drunk, and can cause infections such as fungi, parasites, and viruses.

Aged water, also known as stagnant water, is water that has been stored for a long time and cannot be moved, and there are very few active water molecules in this water, and long-term drinking will increase the risk of esophageal cancer and stomach cancer.

Boiling water is water that has been boiled many times, and this water is high in minerals, and drinking it can increase the risk of liver and kidney stones.

Unboiled water is similar to raw water, and it is possible to be infected with fungi and viruses, and it also increases the risk of carcinogenic and teratogenic.

If you boil the water and you boil it a little more, it will produce a substance in it, which is not very beneficial to the human body. Therefore, it is recommended that you do not boil the water again.

Boiling water may seem like a trivial thing in daily life, but in fact, there is a lot of knowledge in it.

1.We usually boil water, just to kill the microorganisms in the water, boiling the water is the best sterilization method. However, the excrement of microorganisms in the water, especially the endotoxin released by the pathogenic bacteria after being killed, cannot be killed at 100, so the water should be boiled for 2 to 3 minutes before turning off the fire.

2.When boiling water, when the water is close to 100, the lid of the pot should be opened to let some of the residual volatile organic compounds in the water volatilize, and then turn off the heat after 2 3 minutes after boiling.

3.Due to the secondary pollution problem of transmission and distribution pipelines and water storage tanks, the water stored in the tap water pipeline for too long should not be boiled directly for drinking. In the morning, the tap should be turned on, and the water should be drained for 5 to 10 minutes before boiling for drinking.

The tap water that comes out can be used to clean floors or toilets, for example. In addition, you can put the water in a container to purify and settle naturally before boiling it for drinking.

4.Water should not be boiled repeatedly, it is best to drink it freshly. Repeatedly boiled water is "thousand boiling water", which is stagnant water, and after drinking, it will accelerate the aging of the human body. If the water is stored for too long, it will be polluted by the outside world, and the water is easy to age overnight to form stagnant water.

Five types of boiled water are not suitable for drinking.

One is the water that boiled on the stove all night. The second is the water that is not fresh in a thermos for many days.

The third is the residual boiling water that has been boiled many times, such as the electric heating water dispenser, which is constantly and automatically heated. Fourth, boiling water in a boiling water boiler that is reboiled overnight or not reboiled.

The fifth is the "foot water" after steaming rice and meat. The reason is: the boiling water that has been boiled repeatedly contains more calcium, magnesium, chlorine and other heavy metal particles, which will have a harmful effect on the human kidneys and cause people to suffer from kidney stones.

In this kind of water, the amount of nitrite increases, and it combines with hemoglobin in the human body to become methemoglobin, causing difficulty in blood oxygen infusion, and the harm to human health will be greater.

When the water is boiled a second time, the nitrite will not increase much. But if you boil it many times, the harmful ingredients will increase.

This pin is called a thousand boiling water. This kind of water is boiled for too long, and the water has a high content of non-volatile substances, such as calcium, magnesium and other heavy metal components and nitrite. Drinking this water for a long time will interfere with people's gastrointestinal function, causing temporary diarrhea and bloating; Toxic nitrite can also cause hypoxia in the body, and in severe cases, coma, convulsions, and even death.

If the water is boiled many times, scale will be produced, and the causes of scale are:

Water containing minerals such as calcium (Ca), magnesium (mg), and salts is called "hard water". Rivers, lakes, wells, and springs are all hard water. Tap water is obtained after river water, lake water or well water has been settled, sediment has been removed, and it is also hard water after disinfection.

When it rains or snows just fall, the water does not contain minerals, so it is "soft water". After the water is boiled, a part of the water evaporates, and calcium sulfate (caso4, gypsum is calcium sulfate containing crystal water) that is not easy to dissolve precipitates. The original dissolved source calcium bicarbonate (Ca(HCO3)2) and magnesium bicarbonate (mg(HCO3)2) decompose in boiling water, release carbon dioxide (CO2), and become insoluble calcium carbonate (CaCO3) and magnesium hydroxide (Mg(OH)2) also precipitate, and sometimes MgCO3 is generated.

This results in the formation of limescale.

Yes, when water boils, it boils.

Because the water is boiled, it does not mean that it has reached 100 degrees, but that the water has been continuously boiling, in our understanding, do not think that 100 degrees is the water boiling, in fact, this is not the truth.

At the same time, in our drinking water safety, for the sake of our health, we should keep the water temperature at about 95 degrees to reach the normal drinking standard, because boiling water to a continuous boiling state is not conducive to our physical health.

Precautions for boiling water:

1. When the water is about to boil (80-90), the lid of the pot should be opened.

Because there are more and more organic pollutants in water now, some substances are volatile and will be volatilized with water vapor when heated. Therefore, when the water is about to boil, the lid of the kettle should be opened to allow these substances to be volatilized to the maximum.

2. Wait about 3 minutes for the water to boil before turning off the heat.

This is because after ordinary water is sent to the waterworks, it is chlorinated to remove impurities such as microorganisms. But at the same time, chlorine interacts with residual organic matter in water to form toxic carcinogenic compounds such as halogenated hydrocarbons and chloroform.

The contents of halogenated hydrocarbons and chloroform are closely related to the change of water temperature and the duration of boiling.

3. Water cannot be boiled repeatedly, it is best to drink it now.

The flowing water has a certain self-purifying effect, and the ideal drinking water is fresh water. Scientific studies have found that water ages quickly. Water molecules are in a chain-like structure, and if the water is not often hit strongly, that is to say, the water is not often in a state of motion, but in a static state, this chain-like structure will continue to expand and extend, becoming aging water, commonly known as "dead water".

Water can be boiled repeatedly. In fact, in daily life, it is rare to repeatedly heat drinking water dozens or hundreds of times, even if you use a water dispenser to heat it more than 50 times, it is not a matter of drinking a few glasses of water to be poisoned. Because people have to eat about nitrite at one time to be poisoned, which is equivalent to more than 80 liters of water, it is obviously impossible to drink so much water at one time.

This is in response to the simple and crude sentence - talking about toxicity out of dose is a hooligan.

Therefore, in general, there is no need to worry about nitrite poisoning or carcinogenic problems after drinking a few glasses of boiled water repeatedly.