What chemical reagent is added to water can reduce the boiling point of water by 20

Boiling is the state in which the vapor pressure of a liquid reaches the saturated vapor pressure.

Saturated vapor pressure is in a closed container, at the beginning of the water molecules continue to escape from the water surface into the vacuum into gaseous state, because the speed of water molecules escaping from the liquid, equal to the speed of gaseous water into liquid water, to achieve dynamic equilibrium, at this time the pressure on the water surface is saturated vapor pressure.

When the temperature of the water is 373K, the vapor pressure reaches 101Kpa, so it boils.

Understand this truth, due to the addition of other molecules, the water surface is not completely water molecules, so the escape speed should be reduced, so the steam is reduced, and the external pressure is unchanged, to reach 101kpa, only continue to increase the temperature, this has nothing to do with what substance is added. This is the law of the Urals.

The law states that the vapor pressure of dilute solutions of non-volatile non-electrolytes decreases in proportion to the molar fraction of solutes in the solvent. It has nothing to do with solute properties.

However, the addition of ethanol and other volatile substances needs to take away the kinetic energy of water molecules, that is, temperature, due to escape. Therefore, the boiling point can be lowered. Not because of its low boiling point, but because of its volatility.

So the steam has been lowered.

And its law says yes.

And, at this time.

The pressure on the surface of the water is the saturated vapor pressure.

When the temperature of water is 373K, to reach 101kPa, add ethanol, the vapor pressure reaches 101kPa, due to the addition of other molecules, it is equal to the speed at which gaseous water becomes liquid water, resulting in water on the surface is not completely water molecules.

The boiling point of water does not change at room temperature.

You can try a liquid with a low boiling point such as alcohol, which can be miscible with water in any way.

This lowers the boiling point of the water as a whole (in fact, the boiling point of the mixture as a whole).

Summary. Potassium nitrate, ammonium nitrate, magnesium chloride, calcium chloride dissolved in water can cause water to rapidly reduce temperature.

What substances cool down quickly when added to water? Both the substance and the water must be at room temperature.

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Potassium nitrate, ammonium nitrate, magnesium chloride, calcium chloride dissolved in water can cause water to rapidly reduce temperature.

The most common is NH4NO3, and ammonium salts such as NH4Cl When NH4NO3 is dissolved in water, it absorbs heat violently, causing the ambient temperature to decrease.

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Solution: (1) Sulfur dioxide has the property of being soluble in water;

2) When the iron wire is burned in oxygen, it emits a large amount of heat, which can produce a high-temperature melt, which will cause the explosion of the gas collector cylinder if it falls directly in the gas collector cylinder

1) When sulfur is burned in oxygen, sulfur dioxide is generated, and the role of water is to absorb the sulfur dioxide generated;

2) The iron wire is burned in the gas cylinder containing oxygen, and the temperature of the melt generated is very high, and the bottom of the bottle will be blown up if it is splashed directly, so a small amount of water is held at the bottom of the bottle, that is, the function of water is to prevent the splashed melt from bursting the bottom of the bottle, so the answer is: (1) absorb sulfur dioxide to prevent air pollution;

2) Prevent the high-temperature melt from splashing down and bursting the bottom of the gas collection cylinder

1. In chemical experiments, the role of water is different, please write what the role of water is in the following pure Paison experiments.

1) When the sulfur is burned in oxygen, the role of the water in the gas collector cylinder is 2) When the iron wire is burned in oxygen, the role of the water in the gas collector cylinder is

Hello. The first thing to say is that boiling point is a physical property possessed by pure substances.

In general, mixtures do not have a fixed boiling point.

For example, glass has no boiling point.

That's why there is. What kind of distillation.

Fractionated. Closed filial piety of vacuum distillation.

But. You gave an example that water and ammonia are specific.

Certain substances can be added to form a kind that can be together: "boiling".

Substance. For water.

I've seen experiments with academics in **.

The azeotrope properties can be formed with water and some alcohols, which can reduce the boiling point of water.

For example, isobutanol, isopropanol, and tert-butanol are used to make an azeotrope with 90% water content, and the boiling point can be reduced to 85-87

After using the azeotropic aqueous solution, the total water consumption increased slightly, but because of the azeotropic effect of water, the boiling point was reduced and the volatilization of water was accelerated.

For an aqueous solution of ammonia.

This is related to the concentration of ammonia monohydrate.

is inversely proportional to the potato state empty

Hope it helps.

This statement is correct.

The case where the boiling point of water is 100 is measured at a standard atmospheric pressure. If the atmospheric pressure is lower or higher than one standard atmospheric pressure, the boiling point of water will be correspondingly lower or higher than 100.

The boiling point of pure water at a standard atmospheric pressure is 100. Correspondingly, if the local air pressure is low, the boiling point of water will decrease, and if the local air pressure is high, the boiling point of water will also increase.

Correctly he said that it is possible, and this description is more flexible.

After all, when receiving low pressure, the boiling point will also change.

Yes, the melting and boiling point of a substance is also affected by the ambient air pressure.

Hello, the first thing to say is that the boiling point is a physical property of pure matter, and the general mixture does not have a fixed boiling point, for example, glass has no boiling point, so there is a distillation of fractional distillation and vacuum distillation operation.

But for example, water and ammonia have the peculiarity of being able to add certain substances to form a substance that can be "boiling" together.

For water, I've seen experiments with scholars that water and certain alcohol solvents can form azeotrope properties, which can reduce the boiling point of water. For example, isobutanol, isopropanol, tert-butanol to make azeotrope with 90% water content, the boiling point can be reduced to 85-87 After using azeotropic aqueous solution, the total water consumption increases slightly, but because of the azeotropic effect of water, the boiling point is reduced and the volatilization of water is accelerated.

For aqueous ammonia solutions, which are inversely related to the concentration of ammonia monohydrate, I hope it will help you.

You can add a little alcohol to the water, and the temperature will come out, but it will cause the steam to contain alcohol ......

Non-volatile compounds are ...... vapor pressure increases, boiling point increases

c. Test question analysis: The boiling point of the liquid is related to the size of the air pressure, the air pressure increases, the boiling point increases;

The air pressure decreases, the boiling point decreases To make the boiling point of water higher than 100, it is necessary to increase the air pressure and move to a high place to heat to reduce the air pressure;

Increasing the heat and extending the heating time have nothing to do with air pressure, only the closed lid is to increase the air pressure, so choose C.

Comments: This question mainly tests students' understanding and mastery of the relationship between boiling point and air pressure

For example, if salt is added to water, the boiling point of the mixture is higher than that of normal water; Whereas, when alcohol is added to the water, the boiling point of the mixture is lower than that of normal water.

Definite (premise: the substance can be dissolved in water), the substance dissolved in water will become a mixture, increasing the boiling point.

The boiling point of pure water at standard atmospheric pressure is 100 degrees Celsius, and it is not pure water after adding impurities.

Put the water in a hood, connect it to the extractor, and gradually pump out the air in the hood, so that the air in the hood becomes less and the air pressure drops, so that the boiling point of the water is lower than 100 degrees Celsius.

Or first boil the water to 100 degrees Celsius (1 standard atmosphere), then seal the container containing water (such as a beaker bottle), and pour cold water at the bottom of the container containing water (upside down), so that the air temperature in the bottle drops, the air is cold, the volume shrinks sharply, and the air pressure (in the bottle) drops, and the boiling point of the water in the bottle is only about 70 degrees Celsius! (Because the boiling point of water decreases as the air pressure decreases).

Air pressure is the pressure generated by the gravity of the air, so if you reduce the amount of air in the container, the air pressure will drop.

Thanks!