Pure water at 10, 20, 50 degrees Celsius pH size

1. The conductivity of pure water at the same temperature.

The values are not the same.

1. Pure water is: industrial pure water and drinking pure water.

2. Industrial pure water: at 25 degrees Celsius.

The conductivity range of pure water at temperature is as follows: ordinary pure water: EC 1 10US cm; High purity water: EC ; Ultrapure water.

ec＝；3. Drinking pure water: EC 1 10 US cm (national standard).

Second, it is generally considered that the resistivity of primary water.

is 18 megaohm centimeters, to be precise, when the theoretical resistivity of pure water is used, the resistivity decreases when the temperature increases).

1. If ion exchange resin and reverse osmosis membrane are used.

The conductivity of pure water is generally below 20 sC;

2. If it is pure water for drinking, the conductivity is generally between 100 and 200 s c (there are also those below 100);

3. If it is tap water, the conductivity is mostly between 300 and 500 s C, and the conductivity of tap water in a few areas is about 800 s C.

Because the ionization equilibrium constant of water increases with the increase of temperature, for example, the original is 10 -14, the concentration of hydrogen ions and hydroxides is 10 -7, pH = 7, and at 50 degrees it may be 10 -13 (specific, there is a numerical value), pH = up.

1. The conductivity value of pure water is different under the same temperature conditions.

1. Pure water is: industrial pure water and drinking pure water.

2. Industrial ruler pure water: at a temperature of 25 degrees Celsius, the conductivity range of pure water is as follows: ordinary pure water: EC 1 10US cm; High purity water: EC ; Ultrapure water: EC ;

3. Drinking pure water: EC 1 10 US cm (national standard).

2. It is generally believed that the resistivity of primary water is 18 trillion ohm centimeters, to be precise, the theoretical resistivity of pure water is when the resistivity is when the temperature increases, and the resistivity decreases when the temperature increases).

1. If it is pure water made of ion exchange resin and reverse osmosis membrane, the conductivity is generally below 20 s C;

2. If it is pure water for drinking, the conductivity is generally between 100 and 200 s c (there are also those below 100);

3. If it is tap water, the conductivity is mostly between 300 and 500 s C, and the conductivity of tap water in a few areas is about 800 s C.

When room temperature is known, [h+=[oh-

mol l, guess again due to the ionization of water (h2

o⇌h+oh-

It is an endothermic reaction, so the temperature rises to 80, and the degree of ionization increases, resulting in [H+=[OH- 10-7mol L, that is, pH 7 Answer: Because the pH of pure water at room temperature = 7, the liter laugh beat is high to 80, and the degree of envy of electric collision increases, so that [H+

OH- 10-7mol L, pH 7

What is the pH of the solution when added in 50 ml of pure water.

At room temperature, the ion product of water is 1 10 -14 pure water [h+] = [oh-] = 10 -7mol l pH = 7

At 100, the ion product of water is 1 10 -12 pure water [h+] = [oh-] = 10 -6mol l pH = 6

The ion product constant of water at 100 degrees is -14 power multiplied by 10.

So, the H+ concentration is multiplied by 10 to the minus 7th power.

So, ph=-logc(h+)=

Directly check 50 degrees is the ionic product constant of water, so pH + POH = -LG (

Hence ph=

The pH of pure water is 7 at any degree

Ionization equilibrium of water: H2O <-H+ + OH-

Because the ionization of water is endothermic, when pure water is heated to a higher temperature, the ionization of water is promoted, so the ionization equilibrium constant of water becomes larger, that is, c(h+)*c(oh-) becomes larger, so c(h+) becomes larger.

And pH=-LG[c(h+)] so the pH decreases.

When pure water is heated, the ion product of water increases, and if the ion product of water becomes larger, the concentration of hydrogen ions increases, and the natural pH decreases.

When pure water is heated, the ionization of the water increases, resulting in a greater concentration of hydrogen ions, so the pH becomes smaller, but the pure water is still neutral.

The angle of gas dissolution, the solubility of gas becomes smaller after heating, the proportion of carbon dioxide is high, and the pH is relatively high, which is generally unchanged.

From a physical point of view, the water molecule becomes active and the pH does not change. Even evaporation is water vapor and a small amount of salt.

From a philosophical point of view, the possibility of a smaller pH is that the experiment took particularity as universality.

The hydrogen ion concentration index becomes larger, and the pH becomes smaller.

At a certain temperature, the pH of pure water is, then its PoH value should be:

c.Less than. d.It is greater than withering.

Correct answer to the case of indiscriminate burning: B