In the same environment, which of pure water or salt water evaporates faster?

The boiling point of water is 100 degrees, and the boiling point of salt water is higher than this. Because sodium chloride (refined table salt) is easily soluble in water and decomposes into sodium and chloride ions, which diffuse inside the liquid. Now, if a water molecule wants to become water vapor, it needs to get rid of the shackles of sodium and chloride ions while being attracted by other water molecules.

Water molecules in the liquid state tend to attach to each other to form water droplets, ponds, or oceans. However, water molecules with high energy can overcome this force that binds them together with other water molecules and break away from the surface of the liquid to become water vapor. At any given time, some water molecules detach from the surface of the water, a phenomenon known as "evaporation".

As the water temperature increases, so does the number of water molecules that have enough energy to leave the water's surface. Water boils when the pressure created by the water molecules detached from the surface of the liquid exceeds the pressure of the surrounding air. The water usually begins to boil after heating the water to increase its energy and bring it to a temperature of 100 degrees Celsius.

However, when you add salt to the water, the problem becomes more complicated. Sodium chloride (refined table salt) dissolves easily in water, decomposes into sodium and chloride ions, and diffuses inside the liquid. Now, if a water molecule wants to become water vapor, it needs to get rid of the shackles of sodium and chloride ions while being attracted by other water molecules.

Therefore, pure water evaporates quickly!

Pure water evaporates quickly.

Because in salt water, it is difficult to peel off the water molecules due to intermolecular forces.

Transpiration promotes the absorption of water by roots, promotes the transport of water and inorganic salts in plants, and cannot promote the absorption of inorganic salts.

Photosynthesis consumes water, transpiration transports water Due to transpiration, the concentration of foliar cell fluid increases, absorbing water from the interstitium of the cells, and the interstitium of the cells absorbs water from the cells below, and so on, until the concentration of root cells is higher than the concentration of the aqueous solution in the soil, and then the aqueous solution in the soil is absorbed.

Because crystals are formed, the yield is high, and there is the quality of water in it.

The yield is low due to the following reasons.

1. Too much coarse salt is added during dissolution, which is not completely dissolved, resulting in a decrease in yield;

2. The droplets splash out when dissolving and stirring, resulting in a decrease in yield;

3. During the filtration process, the liquid splashes out, resulting in a decrease in yield;

4. During the evaporation process, the liquid (or solid) splashes, resulting in a decrease in yield;

5. When the liquid is still turbid after filtration, the water will be evaporated, resulting in an increase in yield.

6. After evaporation, the solid is still relatively wet, resulting in an increase in yield.

Evaporation is the only way to separate table salt and water. Only by evaporation can the salt and water be separated. Take advantage of the physical properties of each component in the mixture.

or differences in chemical properties, through appropriate devices or methods, the process of assigning components to different spatial regions or sequentially assigning them to the same spatial region at different times. In fact, separation is a relative concept, and it is impossible to separate a substance 100% from a mixture.

Overview

Evaporation and boiling are both vaporization phenomena and 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 simultaneously inside and on the surface of a liquid. Evaporation of a solution usually refers to the vaporization of a part of the solvent in the solution by heating to improve the non-volatility of the solution.

The concentration (concentration) of a component or the process by which the solute is crystallized out of solution.

Question 1: Is the evaporation of brine into salt and water a decomposition reaction No. The evaporation of brine into salt and water is a physical change, while the decomposition reaction is a chemical change.

Problem 2: Heating the brine causes the water to evaporate, leaving the salt a physical or chemical change 1If boiling water heats liquid water into water vapor, the steam temperature is 100 degrees, which is equal to the temperature of the original water.

2.If ordinary water evaporates into gaseous water, and the water vapor evaporates and absorbs heat, if there is no external heat source, the water vapor temperature is based on the temperature of the original liquid water.

3.To be clear, the temperature of gaseous water is not necessarily greater than 100 degrees Celsius, but can be said to exist from absolute 0 degrees (-273 degrees Celsius) to more than 1000 degrees, so the transformation of liquid water into gaseous water depends on its over-the-top lease. Because it is first and foremost endothermic, if there is a thermal calendar source, the temperature may not change; If there is no heat source to provide energy, the temperature will inevitably drop!

Problem 3: Add salt to the brine, () unchanged, evaporate the water in the brine, () do not change The quality of the water does not change.

The quality of the salt remains the same.

1.Taste the taste.

2.Heating and evaporation, white solid salt precipitation of saturated salt water.

3.Continue to add salt to both, at which point the salt in the distilled water dissolves and the salt in the saturated salt water does not dissolve (because it is already saturated).

Physical Methods Distinguish:

1. Go to a small amount of solution to taste, salty is salted, tasteless is distilled water;

2. Distillation, if there are crystals, it is salt water, and if there are no crystals, it is distilled water;

3 Take a small amount of solution with platinum wire and burn it on an alcohol lamp, if the flame is yellow, it proves that the solution is saline, and the other bottle is distilled water.

Chemical Methods Differentiate:

A small amount of solution is loaded into the test tube, and the nitric acid acidified silver nitrate solution is added dropwise to each test tube, if there is a white precipitate, the original solution is proved to be saline, and the phenomenon is distilled water.

Of course, it is different, pure water volatilizes quickly, and salt water volatilizes slowly.

First of all, salt is not volatile, water is volatile, after mixing, part of the surface of the liquid is occupied by salt molecules, the volatile area is reduced, and the speed is slowed down;

Secondly, the electricity in the water molecule is close to the oxygen atom, so it has a slight negative electric characteristic, and the salt is an ion, in which the positively charged part and the negatively charged water molecule produce a strong rubber absorption force, which also makes the water molecule not easy to get out of the liquid and reduces the volatilization rate.

The mass, initial temperature, and surface area of the two drops of water are the same, and the air flow above the water is also the same. However, one is not heated, and the other is heated, so the student studied the relationship between the speed of evaporation and the temperature of water

Therefore, choose C with the year