All the chemistry knowledge in junior high school Chemistry related knowledge in junior high school

CaCO3 + 2HCl = CO2 + H2O + CaCl2 You can look at the neutralization reaction, which is the acid-base reaction.

Among them, the preparation method of hydrogen, oxygen, and carbon dioxide is more important.

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Mercury is not silver but Hg, pencil is not lead but C, dry ice is not ice but CO2, .,

Physical changes (no new things generated).

Chemical change (there is something new (patina) generated) 2Cu + CO2 + H2O + O2 ===Cu2 (OH) 2CO3

Chemical change (there is something new (copper oxide)) 2Cu+O2=( )=2cuoGenesis that belongs to physical change is Chemical change is 10 Physical properties are Chemical properties

Is it physical or chemical to prepare saline with sodium chloride? Answer: Physics.

Is the ability of copper to form patina in moist air a physicochemical change or a property? Answer: Chemical change.

Copper reacts with oxygen to form copper oxide. Answer: Chemical change.

It is added that in all chemical changes, they are accompanied by physical changes, because chemical changes are always accompanied by light, heat or other phenomena, which are also physical changes in a broad sense, and it is difficult to strictly distinguish them.

As for the dissolution phenomenon, you will know when you learn later, for example, NaCl, there is hydrated ion generation, which is not easy to say is a new substance, and often there are heat changes in the whole process (glucose dissolution will endothermy, and many salts will be exothermic when dissolved). To distinguish them, such processes are also known as physicochemical changes.

Preparation of normal saline with sodium chloride is a ?..Answer:; Physical Is the ability of copper to form patina in moist air a physicochemical change or a property?

Answer: Chemical Copper reacts with oxygen to form copper oxide. Answer: Chemistry.

The physical change is.

The chemical change is.

The physical properties are:

The chemical properties are ---4

Physical Chemical Properties Chemical Changes Physical Changes 359, Chemical Changes 1610, Physical Properties 278, Chemical Properties 4

1.Physical.

2.Chemical changes.

3.Chemical change 2cu + O2 = heating = 2cuo

In turn, there are physical processes, chemical processes, and chemical processes, and the properties they exhibit are physical properties, chemical properties, chemical properties, and oxidation. The criterion is whether a new substance is produced. The answer to the question is Iron rust (chemical process, chemical properties) Water is a colorless liquid (physical process, physical properties) Ore crushing (physical process, physical properties) Basic copper carbonate is easy to decompose when heated (chemical process, chemical properties) Alcohol volatilization (physical process, physical properties) Food decay (chemical process, chemical properties) Gasoline volatile (physical process, physical properties) The boiling point of water at room temperature and pressure is 100 (physical process, physical properties) Electric light is energized and luminous (physical process, physical properties) 10. Paper combustion (chemical process chemical properties).

1.Physical.

2.Chemical change 2Cu + CO2 + H2O + O2 === Cu2 (OH) 2CO3 ( ).

The physical change is the chemical change is the physical property is the chemical property is

Ten. Paper burns, chemical changes.

ps: All objects + verbs are conjugations, objects + adjectives (easy, hard,..Verbs are both properties, whether they are physical or chemical depends on whether new substances are formed.

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A summary of all the knowledge points of junior high school chemistry.

Unit 1: Enter the world of chemistry.

1. Chemistry is the basic science that studies the composition, structure, properties and changes of substances.

2. China's working people's business congress will make bronzes, and iron and steel will be made during the Spring and Autumn Period and the Warring States Period.

3. Green chemistry --- environment-friendly chemistry (chemical reaction conforms to green chemical reaction).

Four characteristics P6 (raw materials, conditions, zero emissions, products) core: the use of chemical principles to eliminate pollution from the source.

4. Candle burning experiment (the name of the product should not appear when describing the phenomenon).

1) Flame: Flame Center, Inner Flame (brightest), Outer Flame (Highest Temperature).

2) Compare the temperature of each flame layer: use a matchstick to put it flat into the flame. Phenomenon: Carbonization at both ends; Conclusion: The outer flame has the highest temperature.

3) Test product H2O: Cover the flame with a dry cold beaker, and there is a water mist in the beaker.

CO2: Remove the beaker, pour in clarified lime water, shake, and become turbid.

4) After extinguishing: there is white smoke (paraffin vapor), light the white smoke, and the candle rekindles. Description of paraffin vapor combustion. 5. Comparison of inhaled air and exhaled air.

Conclusion: The amount of O2 in the exhaled breath decreases and the amount of CO2 and H2O increases compared to the inhaled air.

The inhaled air is the same as the exhaled air composition).

6. An important way to learn chemistry - science**.

General steps: Asking questions, Conjectures and hypotheses, Designing experiments, Experiments, Validating experiments, Recording and conclusions, Reflection and evaluation.

Characteristics of chemistry learning: focus on the properties, changes, change processes and phenomena of substances; 7. Chemical experiments (chemistry is an experiment-based science).

1. Common instruments and methods of use (3) Weighing Tray balance (5) Evaporation protection: At the end of the experiment, first represent a substance C*(5(12、Fuel and energy ((((1、CLPs: stunted growth, reduced yield, underdeveloped root system:

Trace elements (depending on the phase.