Find the high chemistry density of various substances

Actually, what you mean is that you may not be able to tell which is on top and what is on the bottom in extraction

Organic matter: when the relative molecular mass of gaseous organic matter is greater than 29, the density is greater than that of air; Hydrocarbons (alkanes, alkenes, alkynes, aromatic hydrocarbons), lower esters, monochlorohydrocarbons, ethanol, acetaldehyde, etc., which are less dense than water;

The densities are greater than that of water, such as nitrobenzene, bromobenzene, carbon tetrachloride, chloroform, brominated hydrocarbons, ethylene glycol, glycerol, etc. The relative density of hydrocarbon congeners such as alkane, alkene, and alkyne increases with the increase of the number of carbon atoms in the molecule. The relative density of monochloronalkanes decreases as the number of carbon atoms increases. To sum up, all hydrocarbons are less dense than water;

The density of monochlorinated hydrocarbons is less than that of water, and the density of all other halogenated hydrocarbons is greater than that of water;

All alcohols are less dense than water;

All aldehydes are less dense than water;

All esters are less dense than water;

In addition, the density of nitro compounds is greater than that of water.

Inorganics: To judge this question, we must first understand what density is, i.e., the mass of a substance per unit volume. It has two aspects, one is volume (space) and the other is mass.

Next analysis:

Volume: The atomic radius of the atom is large, the volume is large, the leftmost element of the periodic table has the largest atomic radius, the volume is definitely large, and the density is definitely small; Of course, you can also adjust the structure when forming solids, such as the principle of fluffy bread, that is, like inflating (foaming) inside, using this method to make many substances less dense than water!

Mass: You can look at the atomic weight, since water is a compound, you can approximate it with the average atomic weight, i.e., (2+16) 3=6, the higher the atomic weight, the greater the density.

According to the above principle, it is not difficult to judge the density.

For example, NH3, the average atomic weight (14+3) 4=<6, and the volume of NH3 is greater than H2O, so the density is less than H2O.

Na2Si3O7, the density is greater than water, but by foaming, it can also be made less dense than water.

The density of H2, He, Li, Na and K in the element is less than that of water.

Among the compounds, the average density of lithium hydride, beryllium hydride, borohydrate, hydrocarbon, and nitrogen hydrocarbon in hydride is less than that of water.

Other compounds are generally denser than water, but can be made less dense by foaming technology. For example, after foaming, a silicate compound with a density of only one can be obtained.

Among the organic compounds, the density of water is boundary, the density of organic compounds containing only carbon, hydrogen and oxygen is smaller than that of water, the density of monochlorides is smaller than that of water, and the density of bromine compounds is less than that of chlorine, which is more than 1 chlorine atom, and chlorides are heavier than water.

Among inorganic substances, it is generally metallic salt water, but it is not absolute.

Commonly used substance density table (1g cm3 = 1000kg m3 = 1 ton cubic meter), substance density (kg m3), iridium osmium.

Platinum tungsten uranium. Mercury, palladium, lead, silver, copper, iron.

Tin, titanium, diamond, aluminum.

Concentrated magnesium sulfate seawater water.

Ethanol gasoline. The density of p at any point in an object is defined as:

where. v is the volume element containing the p-point;

m is the mass of the volume element. In the centimeter-gram-second system, the unit of density is the gram of centimeters3; In the International System of Units and the Chinese Legal Unit of Measurement, the unit of density is kilogram m3.

Organic chemistry is not a reflection of this Qin, and the analysis of the properties of an organic substance must be studied from the functional groups it contains. Therefore, if you want to learn organic chemistry well, you must study the properties of each functional group and the transformation between functional groups clearly, and you must have a strong awareness of organic synthesis problems, according to the special functional groups of the required products, and the functions of the reactants given.

1. Method:

Put a substance in water:

1) Sinking bottom: indicating that the density of the substance is greater than the density of water;

2) Suspension: indicates that the density of the substance is equal to the density of water;

3) Floating: indicates that the density of the substance is less than that of water;

2. Principle: When the object is in water:

1) Object < water, where the object floats (floats).

2) Object = Water, the object is suspended.

3) Object》 Water, the object sinks to the bottom (sinks).

Most of the questions asked by LZ are organic questions, and attention should be paid to the composition of organic matter, such as hydrocarbon compounds, including alkane, dilute, and alkyne. It contains only CH, and the composition of water is H0, so the hydrocarbon compounds are less dense than water, and if the H in the hydrocarbon is replaced by halogen atoms, then the density of the substance is greater than that of water. For example, 1 chloromethane.

The density of alcohols is smaller than that of water. Then there are acids and esters, LZ should know the esterification reaction of ethanol and acetic acid, the generated ethyl acetate should be absorbed with saturated sodium carbonate solution, we see the stratification, ethyl acetate is in the upper layer, so the ester density of ester compounds (only containing CHO) is smaller than that of water, LZ If you don't understand, please refer to the grease, LZ has never seen the grease under the water surface. As for the problem of dissolving organic matter in water, it depends on the composition of organic matter, and follows the principle of similar miscibility, that is, non-polar molecules are soluble in non-polar solvents, and polar molecules are soluble in polar solvents.

The size of the density in inorganic matter mainly depends on the molecular weight and the molecular weight of water 18, the molecular weight ratio of 18 is more dense than water, and vice versa, remember two typical, ammonia is less dense than water, and sulfuric acid is larger than water. In organic matter, it is also basically related to molecular weight, but there are special cases to remember, for example, the density of hydrocarbons is smaller than that of water, and when there is a substitution of bromine, the density is greater than that of water.

I guess it's on chemical extraction. The halogens in organic are larger than water, the hydrocarbons are smaller than water, and phenol is larger than water, which is actually to be remembered.

Put the substance in the water and see if it settles or floats.

If it sinks directly into the water, then it means that the density of that substance is greater than that of water, otherwise it is the opposite.

1. Hydrogen burns in the air - light blue flame.

2. Hydrogen burns in chlorine --- pale flame, and there is a white mist at the mouth of the bottle.

3. Methane burns in the air --- a light blue flame.

4. Alcohol burns in the air --- light blue flame.

5. Sulfur burns --- faint light blue flame in the air to produce a gas with a strong irritating odor.

6. Sulfur burns in pure oxygen --- a bright blue-purple flame to produce a gas with a strong irritating odor.

7. Hydrogen sulfide burns --- light blue flame in the air to produce a gas with a strong irritating odor.

8. Carbon monoxide burns in the air --- blue flame.

9. Phosphorus burns in the air, white flame, and thick white smoke.

10. Ethylene burns in the air, the flame is bright, and there is black smoke.

11. Acetylene burns in the air, the flame is very bright, and there is thick black smoke.

12. Magnesium burns in the air and emits a dazzling white light.

13. Sodium burns in the air, and the flame is yellow.

14. Iron burns in oxygen, sparks shine everywhere, and the iron tetroxide produced (without flames) melts and drips.

2012 College Entrance Examination Chemistry Review: The Color of Certain Colored Substances.

1.Red: Copper, Cu2O, magenta solution, phenolphthalein in alkaline solution, litmus in acidic solution, liquid bromine (dark brown-red), red phosphorus (dark red), phenol oxidized by air, Fe2O3, (FesCN)2+ (blood red).

2.Orange: Bromine water and an organic solution of bromine (depending on the concentration of the solution, the color varies from yellow to orange).

3.Yellow: (1) Light yellow: sulfur element, sodium peroxide, silver bromide, TNT, experimentally prepared impure nitrobenzene

2) Yellow: silver iodide, pyrite (FeS2), industrial hydrochloric acid (containing Fe3+), long-standing concentrated nitric acid (containing NO2).

3) Brown and yellow: FeCl3 solution, iodine water (yellow-brown-brown).

4.Brown: solid FeCl3, CuCl2 (copper and chlorine gas to produce brown smoke), NO2 gas (red brown), bromine vapor (red brown).

5.Brown: iodine wine, iron hydroxide (reddish-brown), freshly prepared bromobenzene (dissolved in BR2).

6.Green: copper chloride solution (blue-green), basic copper carbonate (commonly known as patina), ferrous sulfate solution or green alum crystals (light green), chlorine or chlorine water (yellow-green).

7.Blue: cholelum, copper hydroxide precipitation, starch meets iodine, litmus meets alkaline solution, copper sulfate solution.

8.Purple: potassium permanganate solution (purple red), iodine (purple black), iodine carbon tetrachloride solution (purple red), iodine vapor.

The color of a common chemical substance.

a) The color of the solid.

1. Red solid: Cu, Fe2O3

2. Green solid: Cu2(OH)2CO3

3. Blue solid: Cu(OH)2, CuSO4

4. Purple-black solid: kmno4

5. Light yellow solid: s

6. Colorless solid: H2O, CO2, diamond.

7. Silvery-white solid: Ag, Fe, Mg, Al, Hg and other metals.

8. Black solids: iron powder, charcoal, Cuo, Mno2, Fe(OH)2, Fe3O4, (carbon black, activated carbon), Fe2S3, Cus, Cu2S

9. Reddish-brown solid: Fe(OH)3

10. White solids: NaCl, Na2CO3, NaHCO3, GA(OH)2, GAO, CuSO4, P2O5, MGO

11. Yellow-green solid: FES

2) The color of the liquid.

11. Colorless liquid: water, hydrogen peroxide.

12. Blue solution: CuSO4 solution, CuCl2 solution, Cu(NO3)2 solution.

13. Light green solution: FeSo4 solution, FeCl2 solution, Feno2 solution.

14. Yellow solution: Fe2(SO4)3 solution, FeCl3 solution, Feno3 solution.

15. Fuch-red solution: KMNO4 solution.

16. Purple solution: litmus solution.

3) The color of the gas.

17. Reddish-brown gas: NO2

18. Yellow-green gas: Cl2

19. Colorless gas: O2, N2, H2, CO2, Co, SO2, HCL gas and other most gases.

Solubility formula.

K, Na, ammonium salt, nitrate, can be dissolved in water;

Chloride insoluble is a silver salt, sulfate insoluble is a barium salt;

Carbonate is only soluble in potassium, sodium, ammonium, potassium, sodium, ammonium, barium tetraalkaline soluble;

There are also four microsolutes: Ca(OH)2, CaSO4, Ag2SO4, and MgCO3.

I'm using a mobile phone, can I pass it to you?

The density of a gas at the same temperature and pressure is the ratio to its phase mass.

It doesn't make sense to ask such questions.

It is advisable to go down and check the information yourself.

In organic matter, pay attention to the composition of organic matter, such as hydrocarbon compounds, including alkane, dilute, and alkyne. Contains only chill, and the composition of water is.

ho, so hydrocarbon compounds are usually less dense than water, and if h in the hydrocarbon is replaced by halogen atoms, then the density of the substance is greater than that of water. (Note: Among the halides of one halogen, the density of fluoroalkanes and chlorinated alkanes is less than that of water; Bromine.

Alkane and iodoalkane are both greater than water, and the density of dichloromeform and chloroform is greater than that of water, and the density of chloroform is and the density of tetraiodomethane is probably the largest.

Comparison of the density of oxygen-containing organic compounds such as alcohols and esters with the density of water:

Esters are generally less dense than water.

The basic density of monoalcohols is smaller than that of water. (The density of lower alcohols is less than that of water, but the density of higher alcohols is greater than that of water, for example: glycerol is denser than water) [Summary].

All alkanes and aliphatic hydrocarbons have a density of less than 1;

The density of monochlorinated hydrocarbons is less than that of water, and the density of all other halogenated hydrocarbons is greater than that of water;

In general, the density of alcohols is less than that of water; (Glycerol extraclass) (lower alcohols are less dense than water, but higher alcohols are denser than water).

Generally, the density of aldehydes is less than that of water; (4 C's or less).

All esters are less dense than water;

In addition, the density of nitro compounds is greater than that of water. (e.g. nitrobenzene).

The density of benzene and toluene is less than that of water. But benzene is denser than toluene.

Benzene and its congeners CNH2N-6

n 6) Insoluble in water, less dense than water.

Halogenated hydrocarbons are denser than water.

Aldehydes, alcohols, lower esters, alkanes, olefins, alkynes, aromatic hydrocarbons, small nitrobenzene, bromobenzene, carbon tetrachloride, chloroform, bromohydrocarbons, ethylene glycol, glycerol and other densities greater than water Bonus points Bonus points Bonus points.

Today, the teacher nagged again.

In general, hydrocarbons and esters are lighter than water.

When the pressure is increased, the volume decreases (v), because the volume of gas before and after the reaction remains unchanged (1+1=2), the equilibrium does not move, the amount of each substance does not change, the concentration increases (c=n v), the mass of gas in the system does not change (m), and the density increases (m v).

The concentration of the product becomes larger, and the balance shift of the reactant becomes larger, and the movement of the equilibrium can only change this change due to the addition of reactants, that is, only a small amount of reactants is less, and the total is still more, so it becomes larger. The second is that the reaction with the same volume of the gas increases and the pressure does not move.