High school chemistry the amount of a substance , the process of rapid and urgent solution

The quantity of matter is the center of calculation, so first convert the quantity of matter:

CH4 i.e. HCl molecule i.e. H2S i.e. NH3 premise: under the same conditions:

1) The order of volume from largest to smallest is: 2 3 1 4 The volume size is determined by the amount of matter.

2) The order of density from large to small is: 2 3 4 1 The density is determined by the relative molecular mass (regardless of the amount of gas).

3) The order of mass from large to small is: 2 3 1 4 The amount of matter can be obtained relative to the mass of the molecule.

4) The order of the number of hydrogen atoms from large to small is: 1 3 4 2 The amount of matter The number of hydrogen atoms in each molecule can be obtained.

CH4= HCl molecule=

h2s= ④ nh3=

1) The order of volume from large to small is 2>3>1>4

Density = m v

2) The order of density from large to small is 2>3>4>1

3) The order of mass from large to small is 2>3>1>4

Number of hydrogen atoms.

4) The order of the number of hydrogen atoms from large to small is 1>3>4>2

Be clear-minded.

The total number of oxygen atoms is the same, but the oxygen atoms provided by each molecule are different, so it is enough to find the amount of each molecule needed to provide the same oxygen atom. This is a type of question.

It takes 1 mol to provide oxygen atom Co, Co2 needs one-half i.e., 03 requires one-third mol

So the ratio is 1:1 2:1 3 and the numerator and denominator are multiplied by six to get 6:3:2

Yes, but the question is about the ratio of mass, so it has to be converted to mass.

2. Sodium: magnesium = 3:2, then the chlorine in sodium chloride: chlorine in magnesium chloride = 3:2*2=3:4 There is always 28mol of chlorine, then the chlorine in sodium chloride is 12mol, and the chlorine in magnesium chloride is 16mol.

That is, sodium chloride has 12mol and magnesium chloride has 8mol

The mass of all sodium chloride is: 12*

The mass of magnesium chloride is 8*95=760g

1. The first question is that you are right, the ratio of the amount of 3:2 Na+ to the amount of Mg2+ = the ratio of the mass of the two substances in the mixture;

2. Because the ratio of the amount of Na+ and Mg2+ is 3:2, the ratio of the amount of Cl- provided by NaCl and MgCl2 is 3:4, and because Cl- is a total of 28mol, NaCl provides 12mol and MgCl2 provides 16mol, which means that the amount of NaCl in the mixture is 12mol, and the amount of MgCl2 is 8mol.

Hope it helps!

1. The ratio of the quantity of matter is m(Na+): m(mg2+) = 3:2 and the ratio of mass is m(na+): m(mg2+) = n(na+) m(na+)) n(mg2+) m(mg2+))).

2. When Cl- is 28mol, the ratio of Cl- is 3:(2 2)=3:4 because the ratio of the amount of Na and Mg ionic substances is 3:2

So the multiplier is 28 (3+4)=4

Therefore, the molar numbers of NaCl and MgCl2 are (3 4), (2 4), i.e., 12 mol and 8 mol, respectively

So their masses are: NaCl: 12

mgcl2::8*95=760g

The quantity of matter and the mass of matter are two different concepts. You say that the quality of things is not a universal statement. If the ratio of the amount of the substance is 3:2, then the ratio of the amount of sodium chloride to the magnesium chloride substance is also 3:2

Right. 2. The ratio of chloride ions in sodium chloride and magnesium chloride is 1:2, and the ratio of the mass of sodium chloride and magnesium chloride is also 3:2, so that sodium chloride is 12mol and magnesium chloride is 16mol, and the mass is sought according to m=nm.

1. The number of electrons outside the nucleus of an atom = its atomic number, the n atomic number is 7, so the number of electrons outside the nucleus is 7, the number of h atomic numbers is 1, so the number of electrons outside the nucleus is 1, and the number of electrons contained in an ammonia molecule = 1 3 + 7 1 = 10. The molar mass of ammonia is 17, and 17 grams of ammonia is 1mol, containing na=Avogadro's constant) ammonia molecules, so 17 grams of ammonia contains 1 10na electrons = electrons.

The mol ammonium ion has 11 electrons, but the ion has 1 positive charge, so it loses one electron, so the number of electrons is 11-1=10. Ammonium ion = . So the number of electrons = 10 Avogadro's constant) electrons.

3. The atomic number of hydrogen is 1, so the number of electrons outside the nucleus is 1The atomic number of oxygen is 10, so the number of electrons outside the nucleus is 8. The number of electrons contained in a water molecule = 1 2 + 8 1 = water = and the number of electrons contained = electrons.

1. N(NH3)=17G 17G Mol=1mol The amount of a substance containing electrons is 10mol, and the number of electrons is 10Na

2. N(NH4+) = The amount of a substance containing electrons is 1mol, and the number of electrons is Na

3. N(H2O)= The amount of a substance containing electrons is, and the number of electrons is.

1) The amount of 17 grams of ammonia substance: 17 17 = 1mol, ammonia is a 10-electron molecule, so it contains 10 Na electrons. or electrons.

How to calculate the number of electrons in ammonia: Nitrogen has 7 electrons and hydrogen has 1 electron, but there are 3 hydrogen atoms with a total of 10 electrons.

2).NH4+ i.e.

n is 7 h and 1

NH4+ contains 7+4-1=10 electrons.

So the number of electrons contained in the ammonium ion is.

1 power electron.

3) Like above, leave one for you to try.

g ammonia gas contains 1mol of ammonia molecules, and each ammonia molecule contains 17 electrons, so a total of 1mol*17=17mol electrons.

2. Same as 1, n= so there are electrons in common.

3. Same as the previous two questions, the number of electrons = 18 * I don't know why the value is not made up is not an integer 3

Writing directly about the process may not give you a good understanding, so I'll write my thoughts and thoughts on these topics.

1.First of all, the relationship between mass m, the quantity n of a substance, and the number of molecules is like this: haven't we studied the relative molecular mass, and noticed that its unit is not, how many grams per mole it represents, that is, the mass is the denominator, it is the strongest, so when the mass, the quantity of the substance, and the relative molecular mass are solved, the mass is the product of the other two quantities, and the other two quantities are divided by the mass by the other.

And the relationship between the quantity of matter and the number of molecules is that there are 1na molecules per mole of substance, and the quantity of matter should be found by mass, so the number of molecules is.

To find the mass of the oxygen atom, you must first find the amount of the sample substance, which is twice that of CO2, so the mass is grams).

2.1mol H2SO4 contains 7 atoms, that is, 1 mol H2SO4 has 1 mol sulfate ions, so the result is mol, and the number converted to is.

3.Mass is the result of the quantity of matter and the relative molecular mass, when the quantity of matter is equal, the ratio of mass is equal to the ratio of the relative molecular mass, or the quantity of matter can also be seen as 1mol (all the problems in this question can be considered in this way). The result is 17:16, and the number of molecules is equal to the amount of matter multiplied by Avogadro's constant, and the result is 1:1

The number of atoms is equal to the amount of matter multiplied by the number of atoms per mole: the result is 4:5

4.The conservation of mass can calculate the mass of c 10+25-17=18, molar mass = mass and the amount of matter = 90g mol

The amount of the substance = the number of molecules =

The amount of oxygen in the substance =, the mass = g

Number of hydrogen atoms =

Number of sulfate ions =

If the quantities of the existing equal substance are one part each of NH3 and CH4, then the mass of NH3 and CH4 = 17 16

The ratio of the number of molecules = 1:1, the ratio of the number of atoms = 4:5 It is known that 10ga and 25 GB are exactly completely reacted to form and 17 gd, then the mass = 10 + 25-17 = 18 grams, and the molar mass = 18 g mol

As long as you read books carefully, it is not difficult to understand that chemistry cannot be taught by teachers, and the most important thing is to read and think by yourself. You're asking basic questions, and it's easy to solve them with the formulas in the book.

The first one is to find the amount of matter first, and then count the number of molecules.

2 is to take one mole of oxygen, the mass is 16g, divide by the number of oxygen atoms in one mole, just multiply 6

17:16 1:1 4:510 plus 25 minus 17 is the mass of c, and then divide by the amount of the substance of c to find it.

1.The molar mass of carbon dioxide is 44g mol, and the mass divided by the molar mass is equal to the amount of matter, i.e., the answer is, the amount of matter of the oxygen atom is 2 times that of carbon dioxide, i.e., the molar mass of the oxygen atom is 16g mol, then its mass is.

2.There are 7 atoms in a H2SO4 molecule, then there are 7 times the number of atoms, that is, the number of sulfate ions is the amount of sulfate ions multiplied by na.

The above process involves two equations.

2NH3+3Cl2---N2+6HCl reaction1NH3+HC---NH4Cl reaction 2

In the last step 1 reacts completely, and 2 reacts to a certain extent.

NH3 is oxidized only in the first process.

It is advisable to set the Cl2 volume to X, starting NH3 A-X, Cl2 X reaction 1 ending NH3 A-X-2 3*X, Cl2 0, HCL2X, N2 1 3*X

Reaction 2 ends NH3 0, Cl2 0, HCl 2X-(A-X-2 3*X).

n2 1 3*x ,nh4cl solid ignores it.

So 2x-(a-x-2 3*x)+1 3*x =b, so x=(a+b) 4

So the volume of NH3 being oxidized is 2 3*x=(a+b) 6 and the answer is correct.

I'm so tired.

In the last question, if you increase 1molNH3 and decrease 1molHCl, then the actual "volume before and after the reaction" should be proportional to the theoretical "before and after volume", which is equal to the actual amount of oxidized NH3 compared to the amount of theoretical oxidation, which is the fastest!

The last thing left is NaCl, and the quality is.

The specific analysis is as follows:

The mixture of sodium carbonate and sodium bicarbonate is only confusing, because the amount of sodium ions is given in the title. As mentioned in the title, the addition of hydrochloric acid to the exact complete reaction means that both sodium carbonate and sodium bicarbonate are converted into sodium chloride (NaCl), regardless of the process of the reaction, bicarbonate ions and carbonate ions react with hydrogen ions to form carbon dioxide and water, and the anions left in the solution are only chloride ions. According to the charge balance, n(na)=n(cl), so n(na)=n(cl)=

Then find m(nacl)=n(na)*m(nacl)=solution completed!

The solid is sodium chloride.

The amount of the substance of sodium chloride is equal to the = yes of the sodium ion.

The mixed solution of sodium bicarbonate and sodium carbonate, adding hydrochloric acid just reacts, only sodium chloride, after evaporation, conserved by the sodium element, n(NaCl)=, m(NaCl)=

The relative molecular weight of copper sulfate pentahydrate is 250

The amount of the substance of copper sulfate pentahydrate is.

Look at cuso9h10

So the panties have drawbacks.

A total of years of envy people.

Contains co-selection c

That is, mol

Because the metal ion is +2 valence, the molecular formula is MCL2 (M stands for 2 valence ion) and because there is, there is mol MCL2

The molar mass is.

The relative molecular mass is 95

The relative molecular mass of the 2-valent metal ion is 95-2* is magnesium ion.