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The average reaction rate expressed by the change in concentration of x over the previous 2 min.

4x（g）＋5y（g）＝nz（g）＋6w（g）x=

Mean reaction rate expressed by the change in concentration of x =

The concentration of y at the end of 2 min is.

4x（g）＋5y（g）＝nz（g）＋6w（g）y=

The concentration of y at the end of 2 min is.

The value of n in the chemical reaction equation is .

The concentration of z at the end of 2 min is 2

z the amount of substance at the end of 2 min

4x（g）＋5y（g）＝nz（g）＋6w（g）--n---6n=4

1) Chemical reaction formula: 4 x + 5 y = n z + 6 w assuming the concentration of x at the end of 2 minutes is amol, 4 6

a has a reaction relation: 4 6=a

i.e., a=, then within 2 minutes, x is used to indicate that the chemical reaction is shorthanded:

2) Chemical reaction formula: 4 x + 5 y = n z + 6 w assuming that the concentration of y consumed at the end of 2 minutes is bmol, 5 6

b has a reaction relation and obtains: 5 6=b obtains b=3) chemical reaction formula: 4 x+5 y=n z+6 w then the concentration of z at the end of 2 minutes is.

From the reaction formula, the ratio of the concentration of z to w is n 6, i.e., n 6 =, and n = 4 is solved

4x(g) 5y(g) nz(g) 6w(g)0 0 before reaction.

After 2min.

1) The amount of change in consumption x in 2 min x

The average reaction rate expressed by the change in concentration of x over the first 2 min is:

2) The concentration of y at the end of 2min is: (

3) The reaction rate expressed according to the change in the concentration of z is obtained: ( mol (l min) mol (l min), so that n=4

1) Reaction ratio: x:w=4:6===> after 2 minutes, the reaction is x=4 6*

x Concentration Change Reaction Average Rate = Concentration Change) 2min (Time Elapsed by Change) = 2) Reaction Ratio: y:w=5:6===> After 2 minutes, the reaction is y=5 6*

The amount of substance at the end of 2 minutes y =

Concentration of y at the end of 2 min =

3) The average rate of concentration reaction of z = the average rate of concentration change reaction.

i.e. v(z) = v(x).

Reaction ratio: v(z):v(x) =4:n=1:1 So n=1 The key to this question: 1. The concept of average reaction rate: the change in the concentration of a substance per unit time. Unit: mol (l*mol).

2. The key in this question is that the reaction vessel is a closed container (implying that the total volume of the substance before and after the reaction is inconvenient) 3. The rest is the understanding of the coefficients in the reaction equation.

c(x) at the beginning, c(y)=

4 x + 5 y = n z + 6 w starting concentration 0 0

Change concentration x

Equilibration concentration x

The first two minutes v(x) (units).

After two minutes c(y) = unit).

After two minutes, c(z) = units).

Then c(z) c(w)=n 6, and n=4 is obtained

The landlord, the mobile phone, laborious, some places the mobile phone is inconvenient to play, lz understand! If you don't understand, please ask additional questions.

The molecular weight of silver chloride is, precipitate, and it is all silver chloride, so there is, that is, chloride ions. Because it is 1 10, FeCl2 with chloride ions in the original solution can only provide chloride ions, so some chlorine is provided by chlorine, that is, the chlorine gas participating in the reaction.

2fecl2+ cl2＝ 2fecl3

From the above reaction, it can be seen that 500ml of FeCl2 is fully oxidized with chlorine, so it is not fully oxidized, and chlorine can oxidize Fe2+

The mass fraction of Fe2+ to be oxidized is.

The diagram is drawn on the computer, and you write the equation yourself.

The total solids added are 29g at the end, indicating that Reaction 2 binds more water than Reaction 1)

Then cao is more than naoh And then you can calculate all the answers by setting equations, and I can't play grass with a computer, so you can calculate it yourself One of the most important information to pay attention to in this question is"Ca2+, CO32- and HCO3- were no longer detectable in the solution"It means that the reactions in the solution are just completely reacted.

Question 2: From the ratio of the number of protons to the number of neutrons is 11:13, it can be seen that the mass of the element is a multiple of 24, and the relative molecular mass of the element is a multiple of 29, which is about multiplied by 48, so it is titanium, and the atomic mass of halogen is 142, and 142 is 4 times that of chlorine.

So the chemical formula is period 4, group ivb in the periodic table.

no, that is, from the original no3-, to the current no, the total number of electrons = will be obtained.

In aluminum-mafic alloys, they were all elemental, but now they are all ions, and they should lose electrons in total, that is, they have a positive charge. So when it comes time to react with OH-, it should react with OH-.

But the solution may also contain H+, which is conserved by charge: n (positive charge) = n (negative charge), and n (positive charge) = n (h+) n (negative charge) = n (residual no3-) = n (original total hno3) - n(no) = - mol = mol

n(h+)= mol

So in the end, n(naoh) = n (negative charge) + n (h+) =

So V(NaOH) = 3 mol L = L = 150 ml

This question is calculated according to the conservation of electrons.

The electron loss of the metal is equal to the electron gain of the NO3- ion, and the metal ion in each valence state is combined with an oh- to form a precipitate! ）

no3- no (3 valence).

Hence no3- 3e- 3oh-

n(no3-)=

n(oh-)=

The amount of nitric acid can be obtained from n=c*v, so the amount of n element substances is Because the amount of nitric oxide substances can be found as, so the amount of n substances in nitric oxide is So the amount of total substances of n in the generated aluminum-mafic iron salts is Because the ratio of salt to alkali precipitate is anion and cation, so the amount of NaOH is equal to the amount of n in salt = Because sodium hydroxide is 3mol l, v=150ml is obtained from v=n c

According to the conservation of nitrogen, the nitrogen in nitric acid is eventually converted to NO and sodium nitrate.

Let the volume be v, then.

Get 150ml

There is no way to do this, and teaching you the method is not right away, mainly by writing more questions by yourself, and after writing more questions, you will form your own thinking pattern, and you will summarize the method.

1）3o2===2o3

Let the imitation slag reed have 1molo2, if 30% of the oxygen is converted to ozone in the above reaction, yes, the average molar mass of the gas mixture is 32 g Liangshen mol2)3O2===2O3 V

x x = 3 l ozone 3 l

3) n=Let O3 be ymol and O2 be Zmol

y+z=48y+32z= y=

The volume fraction of ozone in the mixture is .

The last backup question O2 and O3 are all absorbed by copper, and the difference method cannot be used.

(rcoo)3c3h5

n(h2)=

There are two double bonds or one triple bond in r- (r:cxh2x-1-) 6x+1+3=106

x=17

There are 2 c=c bonds in each acid molecule.

Let the chemical formula of a be (CNH2N-3COO)3C3H5

cnh2n-3coo）3c3h5 --3（n+2）co2 +（3n-2）h2o

1 3（n+2） 3n-2

1/（6n+4）=

The structure of n=17a is (C17H31COO)3C3H5+6H2=catalyst, pressurized = (C17H35COO)3C3H5

c17h35coo）3c3h5+3naoh===3c17h35coona+ch2（oh）ch（oh）ch2（oh）

This problem can be solved using the cross method, c2h4 28 3

29 (the number obtained by subtracting the small one from the larger one on the diagonal line is the ratio of the quantity of matter, which is also the volume ratio) o2 32 1

The cross method is actually the most commonly used application of the limit idea in chemistry, the density of the gas is only related to the molar mass of the gas, one extreme is that there are many acetylenes, the limit is that the oxygen is 0, all acetylene, then the average relative molecular mass of the gas = acetylene relative molecular mass = 28

Also at the other end is 32, and the average relative molecular mass of the actual gas is 29, which is somewhere between the two, so it's a mixture of them.

So the ratio of their quantities is 3:1, and then suppose that this gas is a mixture of 3 mol of ethylene and 1 mol of oxygen, and the total mass m=3*28+1*32=116 so the mass fraction w=3*28 116=

I don't know if you understand, you can ask questions if you have any questions.

Ratio of density = ratio of relative molecular mass Therefore, the average molecular weight of C2H4 and O2 is crossed by the method: C2H4 28 329O2 32 1, that is, the ratio of the amount of C2H4 to O2 is 3:1 (note that the ratio solved by the cross method is the ratio of the amount of matter).

Set 3molc2h4 1mollo2

3molc2h4 mass 84 1molo2 mass 32 mass fraction = 84 (84+32)=

The mass of water is known to be the amount of the substance that is hydrogen-decomposed and the amount of the substance that is carbonized by the ratio of the hydrocarbon in ethanol to the hydrocarbon.

use, to obtain the total mass of CO and CO2.

Let the quantity of the substance of Co be x, the quantity of the substance of CO2 be y, and the system of equations gives xy=

28x44y=

The mass of x=co is .

This problem can use the magic cross method in chemistry, which is not easy to operate I will demonstrate ethylene 28 3 in general

29 (the number obtained by subtracting the small one from the larger one on the diagonal line is the ratio of the quantity) Oxygen 32 1

So the ratio of their quantities is 3:1, and then suppose that this gas is a mixture of 3 mol of ethylene and 1 mol of oxygen, and the total mass m=3*28+1*32=116 so the mass fraction w=3*28 116=

I don't know if you understand, you can ask questions if you have any questions.

First calculate the concentration of the concentration of the amount of concentrated hydrochloric acid of the substance.

Equipped with a v ml volume of concentrated hydrochloric acid.

v= ml

The amount of hydrochloric acid substances that are grasped is constant.

Utilize n=m m=c*v and c1*v1=c2*v2

calculate, remember the units.