Where are the chemists? I ve had so hard looking for you!!

Analyze first when you get the topic: sodium hydroxide, that is, hydroxide, can form precipitates with silver ions and calcium ions; Potassium sulfate, also known as sulfate, can form precipitates with these three metal ions; Hydrochloric acid, also known as chloride ions, can only precipitate with anions.

Well, the first step must be to add hydrochloric acid, because adding the other two will not only produce one precipitate. After adding hydrochloric acid, the silver ions are precipitated, and there are calcium ions and barium ions left, so sodium hydroxide must be added, because the addition of sulfate will generate calcium sulfate and barium sulfate two precipitates. After adding sodium hydroxide, calcium hydroxide precipitate is generated, and barium ions are left, so finally potassium sulfate is added to generate barium sulfate precipitate.

So the answer is 312, all four options are wrong haha, you copied the wrong question.

I didn't pay attention to it, but I also had the equation - -

Step 1: AG+ +Cl- === AGCL (precipitation) Step 2: CA2+ +2OH- === CA(OH)2 (precipitation) Step 3: BA2+ +SO42- === BASO4 (precipitation).

Every option is wrong and should be 312

If excessive sodium hydroxide is added first, silver ions and calcium ions will be precipitated, and it is not satisfied.

If potassium sulfate is added first, then all ions will precipitate, and it is not satisfied.

Therefore, hydrochloric acid is added first to precipitate the silver ions.

Next, if potassium sulfate is added, then in the same way, calcium ions and barium ions will be precipitated, not satisfied.

Therefore, sodium hydroxide is added to precipitate off calcium ions.

Finally, potassium sulfate is added to combine with barium ions to produce a precipitate.

Look at the solubility table at the back of the book to see it at a glance.

Step 1: Add hydrochloric acid.

Reaction: AG+ +HCl = AGCL (precipitation) +H+ Step 2: Add NaOH

2NaOH + Ca2+ = 2Na+ + Ca(OH)2 Step 3: Add K2SO4

k2so4 + ba2+ = baso4 + 2k+

Add hydrochloric acid first. Identify silver ions.

If potassium sulfate is added.

then the barium ions will be identified.

It is a white precipitate.

Calcium ions produce slightly soluble calcium sulfate.

Of the options you give, b is more appropriate. Note that Ag2SO4, CaSO4 is a slightly soluble substance, Agoh is insoluble, but easily decomposes.

It should be 312! The answer is no.

b add hydrochloric acid to identify silver ions, then add potassium sulfate to identify barium ions and finally add sodium hydroxide, because sodium hydroxide and silver ions and calcium ions can produce white precipitates, can not be added first, potassium sulfate and calcium ions and silver ions all produce microsolubles, can not be identified! So b right!

The number of protons in the nucleus is 5, and it has neutron numbers of 5 and 6 in nature.

It shows that the relative atomic masses of the two isotopes differ by 5+5 = 10 and 5+6 = 11

According to the crossover method of the Ten Xiang manuscripts, the ratio of the number of these two isotopes in nature = 11 - 10) = 1:4

So the ratio of numbers in nature = 1:4

The atomic mass = the number of protons + the number of neutrons.

So the relative atomic masses of the two isotopes are 10 and 11

Cross: The number of neutrons is 5 and 6, and the ratio of the number of two isotopes = (brother in the row: (:4

The number of protons is 5 and the element is b

10b 11b (numbers are superscript).

Let the 10b contained in the sedan car source be x, then the 11b contained is 1-x10x+11(1-x)=

x=x=The ratio of the two isotopes to the number of closed brightness in nature is: 4

Phenol + sodium hydroxide = sodium phenol + water.

Sodium phenol is a salt that is soluble in an aqueous solution of sodium hydroxide.

Benzene is insoluble in aqueous solution of sodium hydroxide, and there is obvious stratification.

Therefore, benzene can be extracted with this stratification phenomenon and a small amount of phenol can be removed.

Phenol, also known as carbolic acid and hydroxybenzene, is the simplest phenolic organic matter, a weak acid, and sodium hydroxide is a strong base, and a chemical reaction can occur between them, so as to go out phenol, and sodium hydroxide and benzene will not react.

Phenol is a very weakly acidic organic substance, whereas benzene is a neutral organic substance! The latter is not miscible with water. The former produces sodium phenol, which is soluble in water!

8) The amount of KMno8 species participating in the decomposition reaction is, and the amount of remaining KMno8 species is, calculated according to the chemical equation. 8kmno8== k8mno8 + mno8 + o8↑ 8kmno8+88hcl==

The electrode reaction formula of the negative electrode is:

The electrode reaction formula of the Al-3E-+4OH-==ALO2-+H2O cathode is:

ag2o+2e- +h2o===2ag +2oh-

The negative electrode undergoes an oxidation reaction and loses electrons.

Al-4E- 4OH-==AlO2- H2O, which is problematic Charge is not conserved, it is wrong.