See a sophomore chemistry question about the rate of reaction .

Since acetic acid is a weak electrolyte, there is a CH3COO- +H+ == CH3COOH (reversible reaction) equilibrium, when the acetic acid is added, it will combine with the hydrogen ions in the solution, so that the free hydrogen ions in the solution will be reduced, that is, the concentration of hydrogen ions in the solution will be reduced, of course, the reaction rate with iron will slow down, but as the reaction progresses, the hydrogen ions in the solution are gradually consumed, and the acetic acid molecules in the solution will dissociate hydrogen ions, and the reaction continues. It doesn't matter if you add too much ch3coona, the total amount generated in the end is the same, but if you add too much, the reaction rate will slow down a lot, and the same reaction time will be longer, so you can add an appropriate amount.

ch3coo- +h+ == ch3cooh This is a reversible reaction, so when ch3coona is added to water, a part of the hydrogen ions reacts with acetate to form acetic acid, which slows down the reaction with iron, with the consumption of hydrogen ions, acetic acid re-releases hydrogen ions, reacts with iron, and knows that the hydrogen ions are completely consumed, and the amount of hydrogen produced is not reduced.

However, if an excessive amount of sodium acetate is added, it indicates that there is an excess of acetic acid, which will compete with iron for hydrogen ions, resulting in a part of the hydrogen ions combining with acetate and not reacting with iron, reducing the production of hydrogen, so it should not be excessive.

Because hydrochloric acid and iron react from the contact surface, the contact surface is limited, so it takes a certain amount of time. Prior to this, hydrochloric acid has been ionized into hydrogen ions and chloride ions in solution. Acetate can be combined with hydrogen ions to form acetic acid, a weak electrolyte, but as the reaction progresses, there are not enough hydrogen ions in the solution.

Acetic acid itself has a certain amount of ionization, which generates hydrogen ions, which will further react with iron, so that the equilibrium will move in the direction of ionization until the iron reaction is completed or the hydrogen ions are consumed. This process obviously slows down the reaction rate.

It may be that the hydrolysis of acetate will produce hydroxide, which will combine with iron ions to form a precipitate.

Because CH3COOH is a weak electrolyte, CH3COO- and H+ will combine to form CH3COOH, the concentration of H+ will temporarily decrease, the rate will decrease, when the concentration of H+ decreases, CH3COOH will ionize H+, so the total amount of H2 produced remains unchanged.

Excess CH3Coona is fine, just don't do it to the point where the solution is alkaline.

（1）8 mol

If the second question follows the first condition, it is very simple, the amount of the total substance is reduced by the same amount as the amount of the substance that produces ammonia, that is, 4mol of N2 and H2 are consumed, 2mol NH3 is generated, and 2mol of gas is reduced, and the equilibrium gas mixture in the first question condition is 32mol, and the amount of the original gaseous substance is 32+8=40mol, and the quantity ratio of the substance is 5:4.

If you don't accept the first condition, there is no equilibrium constant, and it can't be calculated, at least I won't ......

(1)8mol

2) (a+b)/32

Because the total amount of matter of the original gas mixture is (a+b)mol; The volume of the gas mixture when the reaction reaches equilibrium is under the standard condition), i.e., it is equivalent to, so n(start) n(flat) = a+b) 32

2.Because the N2 reaction is 4mol and the H2 reaction is 12mol, and when the reaction reaches equilibrium, the volume of the gas mixture is L (under standard conditions), where the content (volume fraction) of NH3 is 25%. Therefore a = 16 and b = 48.

Therefore, the ratio is 64:58=32:29.

Probably not. Support upstairs.

What is the concentration???

The amount of substance per unit volume of the gas.

Under the condition of constant capacity, the amount of the gas substance remains the same, the volume does not change, and the concentration of the substance does not change. The rate of reaction is of course constant.

If inert gas is filled at constant pressure, then in order to keep the pressure constant, the volume will inevitably increase, and the amount of the original gas substance is unchanged, so the concentration of the substance will of course decrease.

At first, the reaction is slow because the temperature is low, and this reaction is exothermic, so later the temperature becomes high, and the reaction becomes faster.

Later, the concentration of the reactants decreased, so the rate slowed down again.

Different external factors dominate in different reaction periods.

The amount of the substance does not change, the volume does not change, so the concentration does not change, and the pressure acts through the change in concentration, and the rate of concentration does not change.

The acceleration is due to the fact that the reaction is exothermic, the temperature is higher, the rate is faster, and then because the nitric acid concentration is smaller.

1. When the volume is constant, the inert gas is filled, and the pressure increases. But the definition of concentration is the mass divided by the volume, and neither the mass nor the volume changes, so the concentration does not change, and the reaction rate does not change;

2. At constant pressure, inert gas is filled, and the concentration decreases because the gas volume expands and the mass remains unchanged due to the constant pressure;

3. Since it is originally dilute nitric acid, the concentration becomes lower after a period of reaction, so the rate slows down.

The amount and concentration of the substance = the amount of the substance The volume of the thing containing the substance The reaction rate is fundamentally the droplet caused by the change in concentration, and the pressure is strong, but the concentration of the substance remains the same, so the reaction rate does not change.

In c, zinc and copper are only mixed and not in close contact.

In D, the bile alum is dissolved, and the copper generated by the reaction of copper sulfate and zinc is tightly attached to the surface of the zinc to form a galvanic cell, which accelerates the reaction between zinc and sulfuric acid, which is faster than the reaction of C.

Personally, I don't think there should be much difference in the rate of cd. If it's a single choice, select C. The first bile alum, the copper content in the bile alum is 64 250, and the Cu is all replaced with about copper, and the CD rate is the same from this point of view.

According to the title, it will take a while for these things to be mixed, and the bile alum will be dissolved and replaced, so it will be faster to look at c in this way. Conclusion: Single selection C pair, multiple selection CD is OK.

C: Copper: The contact surface of powder is larger and faster than that of flake.

D: There is crystal water in the bile alum and it needs to be replaced, slowly.

a. After coal gasification or liquefaction, it will be fully combusted, which can improve fuel efficiency.

b. The liquid fuel is sprayed out in the form of a mist, which is conducive to the full combustion of fuel and improves fuel efficiency.

c. If there is too much air, there is no need to widen it, and it cannot improve the efficiency of the fuel.

D. Crushing pulverized coal is conducive to full combustion and can improve fuel efficiency.

(1) According to 2SO2 + O2 = 2SO3 (the middle is not an equal sign, it is a symbol of the reversible reaction), the SO2 = participating in the reaction, the generated SO3 = , and the SO3 concentration =.

2) SO2 average reaction rate = (.

3) According to the reaction equation, O2 = to participate in the reaction, then the conversion rate =

a After coal gasification or liquefaction, it will be fully burned to improve fuel efficiencyb Liquid fuel is sprayed in the form of mist, which is conducive to full combustion of fuel and improves fuel efficiency, c Too much air is not needed, and can not improve the combustion efficiency of fueld d Pulverized coal is crushed, which is conducive to full combustion and can improve fuel efficiency.

Solution: The problem of fuel combustion efficiency is actually the problem of the depth of positive reaction of chemical reactions.

All methods are to change the reaction conditions to make the positive reaction more thorough.

For example, changing the state of the fuel, increasing the area of contact with reactants, increasing the reaction temperature, increasing the pressure, or using catalysts, etc.

A gasification and liquefaction of coal can increase its contact area within which it is fully burned with air.

b.Liquid fuels are sprayed out in the form of a mist, and the same goes for them.

c.Introducing a large excess of air is at fault. Although this can also improve the combustion efficiency, the right amount of air is enough, and the excess is wasted, which reduces the efficiency.

d.Crush pulverized coal, the same as a, b.

a, b, d are all speeding up the reaction by increasing the contact area, correct.

However, the introduction of a large amount of air in C will cause the heat to be carried out by the air, which will reduce the combustion efficiency.