Chemistry, human, solve

This is probably going to be the calculation of the ionization equilibrium and the corresponding acid-base k, as well as the influence of temperature. I'll try it.

hac===(h+) ac-)

k ionization = [h+] [ac-] [hac].

Ac-) H2O === HAC + OH-K hydrolysis = [HAC] [OH-] [AC-].

K ionization*k hydrolysis=[H+][OH-]=KW=10 (-14), check the table to obtain the standard state, K ionization=, let [OH-] be X, K = [HAC][OH-] [AC-]=X 2 (1-X)=10 (-14) K ionization = (4 7)*10 (-9).

The formula is a bit complicated, skipping the calculation process, and the calculation is obtained.

x=[oh-]=

h+]=ph=The salt effect is not taken into account here, and after the introduction of the activity coefficient, it is really unbearable.

The enthalpy of dissociation of weak acids is small, and the temperature is negligible in the calculation.

It is true that NaCl is neutral, usually pH is 7 (temperature changes, pH value also changes), sodium acetate is a strong alkali and weak salt, hydrolysis is alkaline, and pH is less than 7

pH = 7 for NaCl

pH>7 of Na2CO3 Because carbonate is easily hydrolyzed, absorbing hydrogen ions, and there are free hydroxide ions in the solution, the solution is alkaline.

The numerical value cannot be calculated.

NaCl is soluble in water and is neutral.

Sodium acetate dissolves in water because of acetate, which is weakly alkaline.

I don't know the rest :p

To analyze whether the reversible reaction has reached chemical equilibrium, the main purpose is to grasp the principle that the variable is unchanged, that is, the equilibrium. That is, to see if a given physical quantity changes under a given condition, and if it does, when it does not change, it reaches equilibrium.

When the pressure does not change, the equilibrium is reached, and the amount of gaseous substances before and after the reaction does not change, and the pressure does not change, so it is impossible to determine whether it is equilibrium or not.

Two density: the volume of the container is fixed, and there are solids involved in the reaction, so the mass of the gas changes with the progress of the reaction, and the density of the gas changes accordingly, so the density does not change to reach equilibrium. The density of 356 is always the same.

Three densities: the density of the 123456 is unchanged and reaches equilibrium. Of these, 124 are ibid. Although the mass of the gas in 356 does not change, the quantity of the gaseous substance changes, and the volume of the gas changes under constant pressure, so the density changes, so the density does not change to reach equilibrium.

4. The average relative molecular mass of a gas is equal to the ratio of the total mass of the gas to the total mass of the gas. The mass of the gas changes in 124, the quantity of the substance does not change, so the relative molecular mass changes, and the mass of the gas in 356 does not change, the quantity of the substance changes, and the relative molecular mass changes. So it's all in equilibrium.

1-butanol oxidized to 1-butyraldehyde, 2ch3ch2ch2ch2oh+O2 - 2ch3ch2ch2cho+2H2O, 2-butanol oxidized to 2-butanone, 2ch3ch2ch(OH)ch3+O2 - 2ch3ch2coch3+2H2O

A (incorrect, 10 g A and 20 g B may not be exactly a complete reaction,) B (not necessarily, NaHSO4 + NaOH = Na2SO4 + H2O) C (incorrect, there is not necessarily water formation in the metathesis reaction) D (correct, displacement reaction definition).

A galvanic cell is a device that converts chemical energy into electrical energy, whereas an electrolytic cell is a device that converts electrical energy into chemical energy. From the total ion equation of the reaction, it can be seen that the hydrogen gas is replaced by Cu in the reaction, which cannot be carried out spontaneously (activity: Cu > hydrogen), and there must be an external power supply, so it cannot be a galvanic battery.

Analysis: 8

Option A is correct], phosphorus pentoxide P2O5, which is composed of only oxygen and phosphorus, meets the definition.

Option B is false], potassium chlorate kclo3, it belongs to the salt class, a certain acid, it is a salt.

Option C is false], potassium permanganate KMNO4, it belongs to the salt class, and a certain acid is a salt.

Option D is false], oxygen O2, which is elemental, not a compound.

So choose A9[Option A is correct], ozone O3, which is elemental, not a compound, and meets the definition.

Option B Error], silica SiO2, which is an oxide, not an element.

Option C is false], potassium chloride KCL, it belongs to the salt class, and a certain chemical is a salt, not a elemental substance.

Option D is false], H2CO3 carbonate, which is a compound, not an elemental substance.

So choose A

(1) According to the law of conservation of mass.

2) According to the reaction formula, potassium chlorate is required to produce oxygen, and then manganese dioxide can be known from the law of conservation of mass, and the remaining solids after adding 20g of water to the solid after the reaction indicate that the solute potassium chloride is dissolved. Therefore, add 20 more water to dissolve, then the remaining solid mass m = ,3) by (2) so 100g can dissolve potassium chloride, so the solubility is 32g 100g solvent water.

4), so the mass fraction of oxygen in the original mixture [(

Knowing the relative atomic masses of iron and oxygen, let the ratio of ferric-oxygen number x:y take the first problem as an example: 56x 16y=7:3