High school chemistry problem concentration please 3Q

KCl does not react with chlorine, the mass before and after the reaction remains unchanged 2KBR+CL2=2KCl+BR2 Because chlorine is excessive, so KBR is used as the calculation benchmark, KBR relative molecular mass is 119, KCL relative atomic mass is So when every 119xgKBR reaction, generated, the mass of the solution decreases here the mass is reduced = i.e. So the KBR mass of the reaction is 119X = the amount of br-ionic substances = the amount of KBR substances = the amount of CBR-ionic substances =The amount of kcl species = the amount of k + ionic species = the amount of cl- ionic substances + br = the amount of ionic substances = so the ratio of k + ions, cl-ions, br- ionic substances is ::2:1

That is, the reduced mass is: gram of the original br xmol cl2 + 2 kbr == 2 kcl + br2 br2 cl2 2 160-71 = 89 x solution x ....Actually, I just thought that this question should not be so troublesome, because in the original solution, the amount of K is the sum of Cl and Br, so I should choose answer A.

(1) The amount of 20 * 14% + 30 * 24% = 10 g of NaCl mass of 10 g g * mol -1 = 20 117 mol NaCl.

20 + 30 = 50 g mass of mixed solution 50 g 1000 23 cm3 = 1 23 l volume of mixed solution.

Divide the amount of NaCl by the volume of the mixed solution.

20 117)mol (1 23 l) = 460 117 mol l is approximately equal to mol l

2) It can be calculated by mass fraction equality.

The mass fraction of NaCl in the above mixed solution is:

10g /50 g=20%

Therefore, the mass of NaCl is X

Column equation x (1000+x) = 20%.

Solution x = 250g

Then calculate the amount of NaCl substance.

n=250g g*mol -1 = approximately equal to answer. Come to an end.

Mass of bl water = b 10 3 g.

The amount of ag ammonia = ag 17g mol = a 17mol the mass fraction of ammonia = a (b 10 3 + a) the volume of the solution = (b 10 3 + a) cg cm 3 = (b 10 3 + a) cml = (b 10 3 + a) c 10 3l

The amount concentration of the ammonia substance = (a 17) [(b 10 3 + a) c 10 3]mol l

The mass fraction is a (1000b+a).

The concentration is [1000 C A (1000B+A)] 17

Since it is an equal volume, the volume is set to 1L

n(cuso4)=

n(h2so4)=

If the total volume does not change after mixing, then c(cuso4)=

c(h2so4)=

c(cu2+)=c(cuso4)=

c(h+)=2c(h2so4)=

c(so42-)=[n(cuso4)+n(h2so4)]/v=

Concentrated sulfuric acid has water absorption, concentrated sulfuric acid will become thin in a poorly sealed container, and when dilute sulfuric acid is configured, concentrated sulfuric acid is added to it without the water that needs to be added before water absorption, so the concentration is small.

Concentrated sulfuric acid has strong water absorption, and it becomes thin by absorbing moisture in the air when it is not well sealed. So if you still dilute it at the original concentration, of course it will become thinner, and the concentration will become smaller.

Because concentrated sulfuric acid is absorbent, it will inhale moisture in the air when placed in a poorly sealed container for a long time, making the concentration of concentrated sulfuric acid smaller.

Because concentrated sulfuric acid is absorbent, it absorbs moisture from the air.

The hydrogen ion concentration and pH are different concepts, and the relationship between them is that the higher the H ion mass concentration, the lower the pH of the solution. The pH size of the solution is determined by the H ion and not the OH ion (the calculation depends on the situation, sometimes it can be calculated using OH). Acetic acid is a weak acid, incomplete electrolysis, so the mass concentration of acetic acid with pH of 1 is greater than that of Naoh, and Naoh is a strong base and completely ionized, so its concentration is, obviously the mass concentration of acetic acid is greater than the concentration of NaOH at this time, so the pH of the solution after the reaction is not the same as the acidity and alkalinity of the same mass concentration after the reaction.

pH: The former is less than the latter.

(1) The concentration of hydrogen ions corresponds to pH: pH = - LG [C (hydrogen ions)].

2) Acetic acid is a weak electrolyte. That is to say, in the acetic acid solution, only a small part of the acetic acid molecules are ionized, while most of the acetic acid still exists in the solution in the form of molecules. Therefore, if the pH of an acetic acid solution is 1, the concentration of hydrogen ions is, but the concentration of acetic acid is much greater.

That is, the reaction of sodium hydroxide with pH 13 and acetic acid with pH 1 is different from the reaction with acetic acid with the mass concentration of the substance, and the pH of the solution after their reaction is naturally different.

pH and hydrogen ion concentration are the same thing, but it is not the same as the amount concentration of the substance, because acetic acid is a weak acid, and acetic acid with pH = 1 means that hydrogen ions are if you want to ionize so many hydrogen ions, there must be a lot of acetic acid, at least greater than it, so it is equivalent to an excess of acetic acid.

Therefore, if the volume is mixed, the solution is acidic.

Hehe, I've been confused when I'm learning this, and I've just finished your question. 、。Actually, you can look at it this way: 1

Salt is a completely ionized substance put into water, whether it is a strong acid, a weak alkali salt or a strong alkali and a weak salt, for example, ammonium bicarbonate, put it in water, ionize by the root ion and bicarbonate ion, it should be noted that the acid salts of carbonic acid and carbonic acid are mainly hydrolyzed, but the acid salts of sulfuric acid and sulfuric acid are mainly based on electricity, because they are strong acids, ammonium bicarbonate is put into water and ionized by the root ions and bicarbonate ions, the bicarbonate ions will be hydrolyzed, and the bicarbonate ions are hydrolyzed to produce carbonic acid, but the degree of hydrolysis is small So all exist in the form of carbonic acid molecules.

2.You look at what bicarbonate ions are hydrolyzed to generate bicarbonate ions, and then bicarbonate ions are hydrolyzed to generate carbonic acid Hydrolysis is mainly based on the first step, so the degree of hydrolysis of the first step is much greater than that of the second step, so the degree of hydrolysis of bicarbonate ions is not as large as that of carbonate ions. Also, it is double hydrolysis, for example, ammonium bicarbonate, bicarbonate ion hydrolysis, to generate hydroxide ions, ammonium ions are also hydrolyzed, to generate hydrogen ions, but bicarbonate ions are combined with hydrogen ions in water, ammonium ions are combined with hydroxide ions in water, if they react like this, promote the ionization of water, so that the concentration of hydroxide ions and hydrogen ions in the water increases, according to the principle of Le Chartre, the degree of hydrolysis of bicarbonate ions and ammonium ions has increased.

To deal with this kind of problem, you also need to look at the amount of weak electrolyte substances in the solution Ammonium sulfate solution has 2mol ammonium ions, while ammonium chloride solution has 1moi ammonium ions, and their hydrolyzed ion concentrations are different.

It depends on how well you learn chemistry in junior high school, in fact, chemistry is very simple, if you learn it from scratch, in fact, it is a matter of interest, you have to take the initiative to cultivate interest, remember more chemical formulas of common things in life, do your own experiment, look at extracurricular books on chemistry, and some detective ** will involve chemistry. Like these are ways to foster interest. This is all subjective, and there are some objective aspects, for example, teachers, schools, families, you can only improve slowly by yourself anyway, it's okay if you don't get discouraged.

(1) If NaOH solution with pH 10 is used, 1000ml should be added.

2) If pH 2 hydrochloric acid is used, 90ml should be added.

Process (1) NaOH solution at pH 12 at OH-concentration; NaOH solution at pH 11 with OH- concentration, NaOH solution at pH 10 with OH- concentration at OH.

pH 12 NaOH solution 100 ml, where the amount of NaOH is set to add pH 10 NaOH solution XL

x=1L2) when 100ml of NaOH solution with pH 12 becomes 11, the amount of NaOH is reduced from , and the reduced part is neutralized by hydrochloric acid, and only the amount of these hydrochloric acid is required.

The H+ concentration of pH 2 hydrochloric acid solution is, let the pH 2 hydrochloric acid solution be added yl, y=, that is, 90ml