Hurry!!! High School Chemistry Questions. There is a reward for answering correctly

First of all, the error is corrected: manganese dioxide does not react with dilute hydrochloric acid, only with concentrated hydrochloric acid.

The product of the equation is manganese chloride, not manganese dioxide, i.e. mno2+4HCl(concentrated)==mnCl2+Cl2(gas)+2H2O

First, calculate the amount of chlorine in the substance n = mol

According to the equation mno2—2hcl(reduction)—cl2, so mno2 is also the calculated mass g of the calculated w = reduced hcl has.

The following explains why the reduced HCL coefficient is 2.

The Cl in the product MnCl2 is -1 valence, indicating that no redox has occurred.

Cl2 is 0 valent, which is produced by the reduction of chlorine in hydrochloric acid by manganese dioxide.

Therefore, the amount of reduced hydrochloric acid is equivalent to the amount of chlorine in chlorine gas.

Therefore the reduced hydrochloric acid front coefficient is 2

From the title, we can know that it is equivalent to BL, so that from the obtained DL, we can calculate that the mass of the reacted calcium carbide is (, so that the mass fraction can be calculated is (

It can be seen that there is n(oh-)=,n(ca2+)=,n(na+)=, and the following reaction occurs when CO2 is introduced.

co2 + oh- = hco3-

It can also occur if there is an excess of alkali.

hco3- +oh- = co32- +h2oi.When the CO2 gas volume is introduced, it is immediate.

It will consume hydroxide and the carbonate generated will precipitate with calcium ions.

The total number of ions at this time is hydroxide + sodium ion).

ii.When CO2 is .

Hydroxide is consumed, and the carbonate produced precipitates with calcium ions, leaving carbonate.

The total ion number is sodium ion + carbonate).

i.When CO2 is .

It will consume hydroxide to generate bicarbonate and carbonate, and the total number of ions precipitated by carbonate and calcium ions is sodium ion + bicarbonate).

Supplement: I'm a junior in college and I'm studying chemistry. wkw1998 is still not enough to learn...

CO2 reacts with Ca(OH)2 and then with NaOH. The standard gas is. According to the reaction equation, the amount of matter is ,, 0mol

1.No answer, I remember doing something similar.

Option b is ethyl bromide and water, nitrobenzene and water.

Ethyl acetate and sodium acetate.

The question is = of choosing b

However, there is also a problem with b, and sodium acetate is solid =

Seed. Option that thing I don't know what sorry =

4.Acidic potassium permanganate is highly corrosive, and the rubber tube of the basic burette is restored.

Organics) = 2n(h2) =

If the molecular formula of organic matter is CNH2N+2O, then the oxygen consumption corresponding to 1mol of organic matter is n+(n+1) 2-1 2=144 32, and the solution is n=3

Therefore, the molecular formula is C3H6O, and the simple structure cannot be drawn here......However, there are two substances: n-propanol and isopropanol.

X, Y, and Z are the top 20 elements in the periodic table, and can form compound xyz4. The sum of the atomic numbers of the three elements is 44, and none of them are in the same period, but y and z are in the same main group, and the correct one of the following inferences is a

A xyz4 is a water-soluble salt, and x and y can form ionic compound xy correctly. It is an ionic compound

b xyz4 is an ionic compound, and y and z can form ionic compound yz2 is incorrect. is a covalent compound

C xyz4 is a salt that is easily soluble in water, and it is incorrect that y and z can form a covalent compound yz. does not exist

D xyz4 is a salt slightly soluble in water, and x and y can form ionic compound xy is incorrect. MgSO4 is soluble in water

x :mg y;S Z: OA is correct and B is false, forming an SO2 covalent compound.

C is wrong, forming SO2

D false. MgSO4 is soluble in water.

Oh, since y and z are in the same main group but not in the same period, we can know that the sum of the valence of the two is negative, and x, y, and z are the first 20 elements in the periodic table, and it is easy to know that they are s and o, and x is mg, which is easy to do.

Magnesium sulfate is soluble in water, but the solubility is not high, so C is wrong;

Sulfur dioxide and sulfur monoxide are covalent compounds, so b and d are wrong;

The answer is a

As soon as you look at the title, you know that z is oxygen, so y is sulfur, and the rest of x is only calcium. , so it's caso4, and the ordinal numbers add up to exactly 24, and several upstairs are misleading. So the answer is d

YZ4 is an acid ion that you don't need to think about to know that it is SO4, 44-16-8=20

X can only be Ca, and CaSO4 is slightly soluble in water. CAO is quicklime that can directly react with water with a high degree of activity, and is similar to Na2O, Na2O2, K2O, all of which are ionic compounds.

The substance is calcium sulfate, x, y, z must be the 2nd, 3rd, 4th, cycle, otherwise it will not reach 44Add yz to the same main family, and it can be determined. Calcium sulfate is slightly soluble, sulfur dioxide is not an ionic compound, calcium sulfide is an ionic compound, choose d

By the way, X is definitely not MG, the conditions do not match.