How can I distinguish the following groups of substances? What nature each uses when distinguishing

1. Can ignite or smell the smell.

2 can be tasted. 3 Observations.

4. Pass into the clarified lime water.

5. Smell it. 6. Pass into the clarified lime water.

Answer]: Melting point: Since sulfur dioxide is a high bridge-resistant molecular crystal with the lowest melting point, and calcium oxide and magnesium oxide are ionic crystals, the charge of calcium and magnesium ions per mu is the same, but the radius of calcium ions is greater than that of magnesium ions, so the enthalpy of calcium oxide lattice is less than that of magnesium oxide, and the melting point of magnesium oxide is higher than that of calcium oxide, so the order of their melting points from high to low is mgo, cao, so2

Due to bacl2

It is a typical ionic crystal, so the melting point is the highest, while Ccl4

It is a molecular crystal with the lowest melting point, while aluminum chloride and ferric chloride already have some covalent molecular crystals. The melting point of the molecular crystal increases with the increase of the relative molecular mass, and the relative molecular weight of ferric chloride is larger than that of aluminum chloride, so the melting point of ferric chloride is higher than that of aluminum chloride, so the order of melting point from low to high is: CCL4

alcl3fecl3

BaCl2 has the highest melting point because SiC is an atomic crystal, whereas KCl is an ionic crystal with a higher melting point. sncl4

and alcl3

It has partially covalent crystals, while SNCL4

than alcl3

The relative molecular mass is large, and the same reason as above, SNCL4

than alcl3

The melting point is high, so the order of the melting point from low to high is: AlCl3

sncl4kcl，sic。$Hardness: SiO2

atomic crystals) mno2

ionic crystals) CO2

molecular crystals). $Solubility: Zn, cd, and Hg both belong to the second subgroup, and are all 18-electron shell configurations, with large polarization force and deformation, and the larger the radius, the greater the deformation, and they are the same as the easily deformable S2-

With the increase of the radius of Zn, Cd and Hg, the mutual polarization is enhanced, so the covalentity of the sulfides formed increases in turn, and the solubility decreases in turn, so the solubility of Zns cds hgs. $Thermal stability: Thermal stability of alloacids and their salts:

The acid is smaller than the acid salt, the acid salt is smaller than the positive salt, the positive salt charge is the same, and with the increase of the positive ion radius, the reverse polarization of the ion is small, and the thermal stability of the positive ion increases, so h2

co3mg(hco3

mgco3baco3

According to the physical properties of these substances, they are different

1 Sugar and salt--- depending on the taste of the substance, sugar is sweet and salt is salty.

2 Copper wire and aluminum wire--- depending on the color of the substance, copper wire is purple or yellow, aluminum wire is silvery-white.

3 Alcohol and water--- depending on the smell of the substance, alcohol has the smell of wine, and water has no taste.

4 Coal and charcoal--- according to the density of the substance, the coal block has a high density and heavy mass, and the charcoal block has a small density and light weight.

1.Electrolytes, salt water conducts electricity.

2.The color can be distinguished, the copper wire is red, and the aluminum wire is white.

3.If allowed, smell directly, the smell of alcohol is special.

4.Coal blocks contain sulfur, charcoal does not contain sulfur, and sulfur dioxide is inspected after ignition.

A is CO2 because everything else is a metal oxide, only CO2 is a non-metal oxide B is Cu, the others are non-metallic elemental, only Cu is a metal C is O2, the others are metals, and only O2 is a non-metal.

D is H2O, everything else is acid, and this one is neutral.

So it is Cu2(OH)2CO3, basic copper carbonate, commonly known as patina.

(1) The four substances are, in order, A (CO2) B [Cu] C (O2) D (H2O).

2) The interaction of these four substances can form a new substance, which is [Cu2(OH)2CO3] with the chemical name of (basic copper carbonate) and the common name of (malachite, patina).

Only CU in B is metal].

B: Cu, it is a metal, generating Cu2(OH)2CO3, basic copper carbonate, commonly known as patina, malachite.

Cu in B is a metal element, and the other is a metal element, so different landlords may think that H2 is a diatomic molecule, but P has white phosphorus, red phosphorus, and the structure of red phosphorus is too complex to discuss, and the molecular structure of white phosphorus should be P4, that is, the white phosphorus molecule is also a molecular crystal composed of four phosphorus atoms, so hydrogen cannot be separated.

2) The medium substance is basic copper carbonate, commonly known as malachite.

cu(oh)2co3

1.In fact, you can taste it, it's really not good, add water to dissolve to see the conductivity of the solution, the aqueous solution of salt is more conductive than sugar.

2.In fact, you can smell it, taste it, or put a piece of iron in it and see which piece of iron is bubbling, and that is white vinegar.

3.In fact, you can see it by looking at the looks, it is really not safe to put both in hydrochloric acid, which is bubbling, which is iron.

4.In fact, you can't die if you taste it, add water, which dissolves into a transparent, uniform solution, which is sugar, and the rest is sugar.

2 odors and 3 colors.

4. Appearance: Particle size.

Baijiu and white vinegar have different smells and physical properties.

Salt and sucrose

The taste is different from the DAO, the physical properties.

Oxygen and carbon dioxide The burning wooden strip sticks into the gas collection cylinder, extinguishing the carbon dioxide, and burning more vigorously is oxygen; Chemical properties.

Gasoline and peanut oil have different smells and physical properties.

Ice and water are in different states, ice is solid and water is liquid; Physical properties: Pure iron is the physical property of the first color.

Water freezes into physical changes .

Steel rust chemical changes .

Alcohol can be burned in the air by chemical properties .

Sucrose is soluble in water physical properties.

Ammonia is volatile due to its physical properties.

Silver has the strongest conductivity in the metal Physical properties4 and the density of water is 1g cm physical properties.

The third wrong should be the blowing of the test tube, and the other right.

1) Water and alcohol: smell the smell of leaky land, alcohol has the smell of alcohol, and water is tasteless.

2) Salt and flour: soluble in water, salt is easily soluble in water, flour is insoluble in water.

3) Kaisogao copper wire and iron wire: look at the color, the copper wire is red, and the iron wire is gray and black.

White wine and white vinegar.

The smell is different, the physical nature.

Table salt and sucrose.

The taste is different, the physical properties.

Oxygen and carbon dioxide.

The burning wooden strips reach into the gas collection cylinder, extinguishing the carbon dioxide and burning the oxygen more vigorously; Chemical properties.

Gasoline and peanut oil.

The smell is different, the physical nature.

Ice and water. The state is different, ice is solid, water is liquid; Physical.

Pure iron is ** color. Physical.

The water freezes. Physical change.

Steel rusts. Chemical changes.

Alcohol burns in the air. Chemical properties.

Sucrose is easily soluble in water.

Physical. Ammonia is volatile.

Physical. Silver is the most conductive of the metal.

Physical. 4, the density of water is 1g cm

Physical. Typing is not easy, such as satisfaction, hope.

1.Oxygen is pure, air is a mixture.

2.Carbon dioxide does not support combustion, and carbon monoxide can.

3.When carbon dioxide is flushed in, there is no obvious phenomenon in the former, and white precipitation appears in the latter.