A couple of chemistry problems, a couple of chemistry problems

1.Contaminating or even damaging the desktop.

2.Dripping liquid down the bottle can damage the label and make it difficult to distinguish.

3.It should be for the fragile reagent bottle, for fear of destroying it.

4.Disaster.

5.Caused by uneven heating**.

6.When the liquid boils, it splashes and hurts people.

7.There is a large temperature difference between the test bench and the heated test tube, resulting in the test tube**.

8.Mixture: a mixture of two or more substances Pure: a simple substance9

9.The chemical use is generally used as a common oxidant, as well as to support combustion.

1 The reagent enters the glue head, destroying the glue head and contaminating the reagent.

2 Break the label when the reagent is left along the outside of the bottle wall.

3 The next time you use it, you can't open the stopper.

4 Causes a large amount of alcohol to burn and cause a fire.

5. The test tube bursts due to uneven heating.

6 Liquids may be sprayed and injured.

7 Test tubes destroy the surface of the lab table.

8 Only one substance is pure, and a mixture of two or more pure substances is a mixture.

9 This is too much, for example, as a respiratory gas for animals, as an accelerant, as an oxidizing agent, and so on.

The chemical equation of the reaction: NH3 H2O=NH3·H2O (ammonia monohydrate) 2NaOH CO2=NA2CO3 H2O, NAOH CO2=NAHC3 Ammonia is very soluble in water, and the solubility of ammonia is 1:700, that is, 1 body.

1.The electrons outside the nucleus are arranged in layers, and the energy of each layer of electrons is different, and the gravitational force of the nucleus is also different, so the rate of motion around the nucleus is naturally not a fixed value.

2.The flame color of hydrogen combustion is light blue. Similar flame colors include methane and carbon monoxide when burning.

3.Metallic elements only ** the strength of metallics, generally do not involve the discussion of non-metallics! However, it can also be said that the stronger the metallicity, the weaker the non-metallic property.

The reaction between chloride and alkali naturally completes the process of making weak alkali from strong alkali. The strength of the alkalinity can correspond to the strength of the metallic, and then the non-metallic can be reversed.

4.The valency of an element should theoretically vary from -7 valence to +7 valence. Metals have no negative valence because metals can only lose electrons, and as for non-metals having positive and negative electrons, it is because non-metal atoms can share electrons in addition to gaining electrons.

Therefore, when analyzing the valency of non-metallic elements, it is necessary to accurately determine the type of chemical bond, and then further analyze the valency of the element!

For the valency of k, there are only 0 and +1 valence!

They were all wrong! The flame color of the metal potassium burning is purple! 1：

It's spinning at high speed, not the speed of light. 2: Hydrogen combustion is a pale blue flame.

3: The reaction of chloride with alkali can know the non-metallic properties! 4：

There is no negative valence for metallic elements! Thank you for adopting.

(1) I haven't learned yet.

2) Light blue: hydrogen, sulfur, carbon monoxide.

Blue: Natural gas (CH4).

3) It cannot be detected.

4) Yes....n also has -4

1.I can burn it.

Iron powder, c (partly such as graphite. Carbon black and so on except for some such as diamond which is transparent), copper oxide, manganese dioxide, ferrous oxide.

3.This refers to salt. Most salts are composed of metal ions and acid ions. "Strong acid" refers to strong acid groups such as sulfate ions, nitrate ionization.

Child. "Strong alkali" refers to strong alkali metal ions, such as sodium ions and potassium ions. "Weak acid" refers to weak acid ions such as carbonate ions, acetic acid and heel ions. "Weak alkali" refers to weak alkali metal ions such as iron ions and copper ions.

So strong alkaline weak acidic substance (alkaline): sodium carbonate. Potassium sulfite.

Strong acidic and weak alkaline substances (acidic): ammonia sulfate. Ammonium chloride.

Weak acid and weak alkaline substance (neutral): copper carbonate. Copper chloride.

Strong acidic and alkaline substances (neutral): sodium chloride. Potassium chloride.

All of them are true.

"Decomposition upon contact with water" is correct agoh decomposition into water and silver oxide when exposed to water.

Insoluble in water. It is also correct that agoh decomposes into water and silver oxide when exposed to water, and silver oxide is insoluble in water, so it can also be said that agoh is insoluble in water.

1.The concentration of hydrogen ions in hydropower is less than 10-7 at room temperature, indicating that it is inhibited by acid or alkali. Therefore, this solution can be both acidic and alkaline.

2.Take care of the topic. Colorless solution is required, how can colored ions exist.

Count pH=10 so alkaline.

Colored ions have color, how can they coexist in a colorless solution? If it exists, it's not a colorless solution, it's a colored solution.

1.First of all, it should be discussed at a normal temperature before it can be conclusive.

c(w) = 1 10 -14 of water at normal temperature

C(oh-)=1 10-4 is calculated

The solution pH = 10 is alkaline.

If there is no temperature limit, it is not necessarily sexual.

2.If there are colored ions in a colorless solution and the solution is colorless, it means that the colored ions have reacted and become colorless, and they cannot coexist.

1. Open the cap.

The air pressure inside the bottle decreases.

Carbon dioxide is less soluble in water.

Carbon dioxide in water is rapidly precipitated, releasing large amounts of carbon dioxide.

Bubbles are generated. 2. After drinking in the stomach.

The temperature of the water increases.

Carbon dioxide is less soluble in water.

Carbon dioxide precipitation.

Carbon dioxide gas is produced.

So there will be hiccups.

1.It's not the same.

Isomer 2(ch3) 2ch means two.

CH3 is connected to CH3Hair.

**Vehement. Methane oxygen is just right.

There is no balance in the complete response.

The volume of air gas is hundreds.

than known premises.

N2 accounts for 78%.

O2 accounts for 21%; Follow the methane ignition procedure.

Know: CH42O2

CO22H2O (gas).

Methane and oxygen.

Volume ratio 1:2

**Vehement. Set: gas mixture.

Volume 100l

Methane volume. vl then O2

Volume 2vl; air volume (100-v) l; then (100-v) 21%=2v; Untie.

v=；Therefore, it was made**.

Strong methane. The number of volumes occupied by air.

4.to alkanes.

Said branched chain more. The lower the melting and boiling point.

2-Methylbutane 5c

Pentane 5c due to pentane.

Linear alkanes and pentane.

The boiling point is higher than that of 2-methylbutane.