Chemistry experts are in a hurry!! Chemistry Urgent! The master enters.

1. Greater than 2Because CH3COOH is a weak electrolyte, only part of CH3COOH is ionized in the solution, and C(H+) in the solution has a pH greater than 2

2. Greater than 7, because CH3COONA is a strong alkali and weak salt, CH3COO-+H2O = CH3COOH+OH-, so CH3COONA hydrolysis solution is alkaline.

3. One principle is the ionization equilibrium of weak electrolytes, and the other principle is the hydrolysis of salts to form weak electrolytes.

4, are the two solutions given in the question:

1.Take the solution in a test tube, measure its pH, if pH 2, HA is a weak electrolyte.

2.Take the solution to measure its pH, if the pH is greater than 7 at room temperature, it is a weak electrolyte.

1.At 25 degrees Celsius, is the pH of the solution greater than or less than 2? ：

Definitely greater than 22At 25 degrees Celsius, is the pH of the solution greater than or less than 7? : Definitely greater than 73

Observe and compare the above two questions, and conjecture that there are two principles that prove that a certain acid (ha) is a weak electrolyte.

One is dissociation, that is, ionization; The other is hydrolysis.

4.Write two different principles to prove that HAC acid is a weak electrolyte (write only the scheme): just write according to the process described above, and don't forget the symbol.

1. Greater than 2

2, greater than 7, 3, power balance, strong electrolyte against weak electrolyte.

4. That's your two schemes: 1Take a small amount of HA solution in a test tube, measure its pH A, dilute it 10 times, and then measure PH B, if B is not equal to A plus 1, HA is a weak electrolyte.

2.Take its salt solution (such as NaA) to measure its pH, if the pH is greater than 7 at room temperature, it is a weak electrolyte.

At 25 degrees Celsius, the pH of the solution is greater than 7.

CH3COOH ionization CH3COO- and H+ so it is acidic, because it is a reversible reaction so it is only partially ionized so it is pH greater than 2

CH3COO- reacts with water to form CH3COOH and OH- so OH is greater than 7

2.At 25 degrees Celsius, is the pH of the solution greater than or less than 7? : Definitely greater than 7

Formation of new matter Combustion, heat release, and the formation of new matter.

Physical melting, mass becoming smaller, density changing.

Chemical properties: The properties of a substance in the process of chemical change.

Physical Properties: Properties of matter that exhibit without a chemical reaction CO Physical Properties: Gas.

Chemical properties are: flammability, toxicity.

Chemical change: CO+02 CO2

The ratio of 1 molecule number is 1 1, the ratio of mass 17 18, the ratio of 2 volume 17 18, and the ratio of the number of hydrogen atoms 3 2

27:17 (18 volume NH3 has 54 h, 17 volume H2O has 34 hours, upstairs error)

（1）∆g=-rtlnk=∆h-t∆s

h/t=∆s-rlnk

h(1 t 1 -1 t 2 )=rlnk 2 k 1 to get h= kj mol

2) Directly substitute the K of 940k to get.

g=（3）∆s= (h-∆g)/t=186j∙k^(-1)∙mol^(-1)

5 L of CH4 and 20 L of O2, the ratio of the two = 5:20 = 1:4

According to the reaction equation, the ratio of the two reactions is 1:2

Indicate O2 overdose.

So it should be calculated according to the amount of ch4.

According to Avogadro's law, the molar volume of a gas at a temperature of 298 vm = =n(ch4) =5 =

n(h2o) = =

m(h2o) =18* =

Is it hard??

Oxygen is sufficient Only methane is considered.

Simple!!!

5 L of CH4 and 20 L of O2, the ratio of the two = 5:20 = 1:4

vm = =

n(ch4) =5/ =

n(h2o) = =

m(h2o) =18* =

Solution: Let the relative atomic mass of the metal be x and the mass of the solute in the sulfuric acid be y.

It can be obtained from the solute mass fraction in the solution after the reaction is 30%, and the mass of MSO4 generated is 50g*30%=15g

MO + H2SO4==MSO4+H2OX+16 98 X+965G Y 15G Solution: X=24 Y=

The metal has a relative atomic mass of 24

Mass fraction of solute in dilute sulfuric acid: A......

Have you learned the concept of Moore?

Forget it, I said it if I didn't learn it.

The mass of MSO4 is 15g

The mass of MO is 5G

Subtracting, the mass of SO3 is 10g, then the amount of its substance is the amount of m.

So, the formula of m is 24 which is magnesium - -c%=

Let the relative atomic mass of the metal be m, and the mass of sulfuric acid in 45g of dilute sulfuric acid is XMO + H2SO4 = MSO4 + H2O

m+16 98 m+96

5g x 50g*30%

This can be found.

Because there is a total weight of 50g before the reaction and no gas is released, the total weight after the reaction is still 50g because the solute mass fraction is 30%.

Therefore, the capacitive mass is 50*30%=15g

That is, let the relative atomic mass of m be x, dilute sulfuric acid contains y gmo + h2so4 - > mso4 + h2o

16+x 98 x+96 18

5 y 15

Write the equation (16+x)*15=5*(x+96) to get 10*x=240

So the relative atomic mass is 24, which is mg

At the same time, y= can be obtained

So the solute mass fraction in dilute sulfuric acid is.