As long as solute is added to the solution, the freezing point of the solution always goes down and

Yes, the number of solute particles in the solution increases, and the vapor pressure of the solution decreases, so the freezing point decreases and the boiling point increases.

Boiling point rises: when the liquid boils, the saturated vapor pressure in the bubbles formed inside it must be equal to the pressure exerted by the outside world, so that the bubbles can grow and rise, so the boiling point is the temperature when the saturated vapor pressure of the liquid is equal to the external pressure, the boiling point of the liquid is related to the external pressure, when the pressure of the liquid increases, its boiling point increases, and when the pressure decreases, the boiling point decreases.

Freezing point decline: freezing point is the temperature of the crystalline substance when it solidifies, different crystals have different freezing points, under a certain pressure, the freezing point of any crystal is the same as its melting point, the same kind of crystal, the freezing point is related to the pressure, the crystal that expands in volume during solidification, the freezing point decreases with the increase of pressure, the crystal that shrinks in volume during solidification, the freezing point increases with the increase of pressure, in the solidification process, the liquid transforms into a solid, and at the same time releases heat, so the temperature of the substance is higher than the melting point when it will be in a liquid state, Below the melting point, it is in a solid state, while amorphous substances have no freezing point.

The freezing point decreases and the boiling point increases:

When the snow wheel is squeezed, it turns into ice, and if it is allowed to turn into water, the problem is solved.

The freezing point of the salt solution is lower than that of ice", to be precise, the freezing point of salt and water is lower than that of water.

For example, the actual temperature is 2 degrees Celsius. Everyone knows that the water has solidified into ice in this environment, but the freezing point of salt water is about 4 degrees. The snow salt mixture does not reach the freezing point, so it melts directly into snow water.

The phenomenon of evaporation occurs when water molecules in the liquid state overcome the constraints of other water molecules and become water vapor from the surface of the liquid. When salt is added to the water, the sodium chloride (table salt) molecule breaks down into sodium ions and chloride ions, which bind to the water molecules. At this time, if the water molecule wants to become water vapor, it needs to get rid of the shackles of sodium ions and chloride ions while getting rid of the attraction of other water molecules, so it needs more energy, so the boiling point of salt water is higher than that of water.

Both the increase in the boiling point of the solution and the decrease in the freezing point are caused by the decrease in the vapor pressure of the solution. For dilute solutions with non-electrolytes that are difficult to volatile, since the vapor pressure drop dp is directly proportional to the mass molar concentration of the solution, the increase in boiling point and the decrease in freezing point of such solutions should also be related to the mass molar concentration.

Here's how it is explained:

If a volatile solute is added to the water, due to the drop in the vapor pressure of the solution, at 0, the vapor pressure of the solution is less than the vapor pressure of the ice, the solution and the ice cannot coexist, and the solution cannot freeze at 0. When the solution drops to a certain temperature below 0, there will be a point where the vapor pressure of the ice and the vapor pressure of the solution are equal, which is the freezing point of the solution, which is lower than the freezing point of pure water. So the freezing point of the solution is always lower than that of the pure solvent.

It doesn't have to be difficult to volatilize electrolytes.

1.Why does the boiling point of water increase when solids are dissolved in water?

At atmospheric pressure (1 standard atmosphere), water boils when the vapor pressure (the pressure generated by water vapor) reaches 1 standard atmosphere. The vapor pressure of water is related to the temperature and the concentration of the water (the fraction of the water molecules in the whole solution particles), the higher the temperature or the greater the concentration of the water, the higher the vapor pressure of the water. The concentration of water in pure water is the highest, when the solid is dissolved, the concentration of water decreases, the vapor pressure of water decreases, and at this time, to make the vapor pressure of water reach 1 standard atmosphere, it is necessary to increase the temperature to meet, so the boiling point of water increases.

2.When water solidifies, solid water (ice) is in equilibrium with liquid water, i.e., water that melts from ice and liquid water solidify into ice at the same rate. When there is a solid solute dissolved in liquid water, the concentration of water decreases, which reduces the rate at which liquid water turns into ice, so that ice dissolution is manifested.

To re-equilibrium, the temperature should be lowered, because the process of turning liquid water into ice is an exothermic change, and according to the principle of equilibrium movement, cooling can shift the equilibrium in the direction of exothermic shift. In other words, in water with dissolved solids, the temperature to achieve the equilibrium between liquid water and ice is lower than that of water with dissolved solids.

That's just a quick rundown. To make it clear, it is necessary to use chemical bits, etc. to analyze. For you to understand, I can only say it simply. Hope you understand.