A few high school chemistry problems, those who can work hard, help and reward

1. Do not react.

2. SO3 ions.

3. When the equilibrium is reached for the first time, let n1=2x n2=3x n3=4x and when the equilibrium is again the reaction n2 is y mol, then 3x-y=

4x+2y=y= y= x= n1=2x-2y=2*

1. Do not react.

2. Carbonate ions and sulfite ions.

and br2 do not react in water because chlorine is more non-metallic (oxidizing) than bromine.

2.Sulfites must not be present because they will be oxidized to sulfate by chlorine gas.

3.Wait a minute, wait for me to figure it out. Come back in a moment.

1.Not reacting.

so33.Well, I wrote it, and if you can't read it, you don't know.

2so2+o2=2so3

xx=I'm afraid you can't read it, it's written very finely.

1 Does not react Fe3+ is already trivalent.

2. Carbonate ions and sulfite ions.

3 The volume reduction reaction shifts to the right, and the amount of SO3 is increased, so that the original is 2a, 3a, and 4a mol, respectively

Let x molso3 be generated, then O2 of and So24A+x= of x are consumed

a= ，x=

So the amount of SO2 ==2A-X=2* mol

Because even if a large amount of CO2 is introduced into ammonia water and reacts with ammonia water to form NH4HCO3, then HCO3- will react with the aqueous solution of SO2, and use relatively strong acid and salt to react with salt to make relatively weak acid and new salt, which can also replace CO2 from the solution, so there is no need to remove CO2 in coal-fired flue gas in advance

In other words, CO2 and SO2 are two acidic gases, the more acidic one reacts with ammonia first, and even if the weakly acidic CO2 reacts first, it will be replaced by SO2 from the solution, so the ion equation given in the answer reflects this meaning, relatively strong acid makes relatively weak acid.

Here he asks whether the presence of carbon dioxide will have an effect on the absorption of sulfur dioxide, and here it is obvious that if carbon dioxide is present, the reaction of HCO3-+SO2=CO2+HSO3- will occur, which means that the presence of carbon dioxide will not have an effect on the absorption of sulfur dioxide!

The valency of R2O8 N-medium R is +(16-N) 2Ro4 and the valency of 2-medium R is +6

When R2O8 N- is converted to Ro4 2-, the R valency decreases to: (16-N) 2 - 6 = 2-N2

The total valency of 5 R2O8 N- decreased: 5*2(2-N2)Mn2+mNo4- increased when converted to Mno4-, and the total valency of 52 mNo4- increased by 10

The valency rise and fall are the same, 5*2(2-n2)=10, and the solution is n=2

The reaction equation is 5R2O8 N- +2mNO4 10Ro4 2- +2 Mno4

The price of mn is +2 +7

So the number of electrons lost by Mn in this reaction is 10, and according to the principle of conservation of the number of electrons gained and lost in the reaction process, the number of electrons gained by r is 10, so (2-n)*10 = 10 so n=1

1、n(hcl) =150 / =

m(hcl) = * =

m(h2o) =1000g

Solution mass: 1000+=

This solution density is wrong, right? Should be.

Solution volume: = 1131ml=

Concentration of the amount of substance: = 6mol l

Quality Score: =

2. First of all, for the convenience of calculation, take 1L of sulfuric acid solution (the density here is wrong?) Or the landlord doesn't understand that ml is milliliter, l is liter)

Let the barium chloride solution x g, and the mass fraction of sulfuric acid is y

Then: m(H2SO4) = 1280y g

bacl2 + h2so4 = baso4↓+ 2hcl1280y m

Solve m(baso4) = m = 3043y g according to the question: x + 1280 - 3043y = x solve: y = 42%.

Then m(h2so4) =1280y =

n(h2so4) = / 98 =

Therefore, the mass fraction of sulfuric acid solution is 42%.

The amount of concentration of the substance.

The amount of concentration of the substance.

c=n/v = 150/ 1000+150/

The amount of HCl substance divided by water + HCl mass and then 2 divided by density to find the volume. Quality Score: =

You can tell by looking at the equations.

The concentration of chloride ions in the magnesium chloride solution is remembered by what he said is that the concentration is not the amount of the substance, so the volume can be ignored.

3.The alkali metal is the metal of the first main group is positive and the hydrogen is Let this metal be x2x+2h20===2xoh+h2 It can be seen that the ratio of the amount of metal to hydrogen substance is 2 to 1

So the amount of the metal is so the formula is b 39 and a reversible reaction will not go to the end, so it is c

Look upstairs, I was wrong about the third question, and I chose it after a glance.

As can be seen from the measurement of the equation, a is 2 to 1, b is 3 to 2, c is 2 to 2, and d is 3 to 2

It has nothing to do with volume, and there is no need to look at the chloride ion concentration at 2 times that of magnesium chloride, which is 2 times that of calcium chloride, 3 times of C and 2 times of D in chloride. Do the math yourself. It is inconvenient to play symbols.

The quantity of matter is easy to say. Alkali metal is a monovalent metal, 2mol alkali metal emits 1molH2, and now 1molH2 is released, then it is. The mass of matter is the molar mass, which is numerically equal to the relative atomic mass.

It is said that it is a reversible reaction, and it cannot be carried out thoroughly, but if it is carried out thoroughly, it will be 2mol. Actually less than.

1. c Write out each reaction formula, the coefficient is the amount of the substance, and the amount of the substance before and after the reaction can be compared.

2. A has nothing to do with the volume of the solution, it is just interference information. The concentration of chlorine in magnesium chloride is that a is in b i am in c and d is in d.

3. B High chemical alkali metals are limited to sodium, potassium and calcium, and can be tried. It can also be excluded by grams, not divisible, which is a trick to do the problem, and generate hydrogen, the molecular mass of sodium 23, sodium excludes; Calcium is 40 and is also excluded; Finally, there is potassium, which can be verified.

4. The C reaction cannot be carried out to the end, the sulfur dioxide is only 2mol, the reaction is reversible, and the sulfur trioxide must always be less than 3mol!

5: C a ferrous hydroxide white precipitate b calcium carbonate white precipitate d hypochlorous acid weak electrolyte, can not coexist in large quantities, and hypochlorous acid is a strong oxidant, will react with iodine ions to form chloride ions and iodine molecules.

6：b a 2al+2oh-+2h2o=2alo2-+3h2↑；c caco3 + 2h+ =ca2+ +h2o + co2↑；d 2h+ +so4 2- +ba2+ +2oh- =baso4↓+2h2o

7:C The sodium peroxide will react with water and carbon dioxide in the air to form sodium carbonate, and finally weathered into sodium carbonate powder EG 2Na2O2+2CO2=Na2CO3+O2; 2na2o2+2h2o=4naoh+o2

Medium ferrous hydroxide precipitation B calcium carbonate precipitation d d Hypochlorous acid weak electrolyte can not coexist in large quantities Select C

Conservation of sodium chloride without complicated calculations.

There is only sodium chloride in the solution, n(cl-)=n(nacl)=

The quality of sodium chloride.

The final solution is NaCl.

n(nacl)=n(hcl)=1mol/l*

m(nacl)=

The final generation can only be a NACL. Because the negative ions in the solution are only chloride ions, and the cations are only sodium ions. Whereas, chloride ions enter the sodium chloride completely. Therefore, the amount of sodium chloride can be estimated from the amount of chloride ions.

cl - nacl

So get solid NaCl. 85g

by the first set of data; Let (NH2)2SO4 have xmol and NH4HSO4 have ymol, then 132x+115y= -- mass relation and 2x+y= nitrogen conservation solution yields x=01 y= From the third set of data, it can be seen that there is (NH2)2SO4 in the sample, NH4HSO4 has, (due to the increase of solid mass, the amount of ammonia decreases, so NAOH is insufficient) NAOH first reacts with NH4HSO4 to form (NH2)2SO4 consumption, (NH2)2SO4 and then reacts with NAOH to form ammonia The amount of NAOH consumed is equal to the amount of ammonia substance, so NaOH is common, then C= Similarly, there is (NH2)2SO4 in the 62g sample, NH4HSO4 has, NAOH first reacts with NH4HSO4 to generate (NH2)2SO4 consumption, at this time (NH2)2SO4 shared, NH4+ shared, and the remainder, so ammonia can be produced, and its mass is .