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MindMap Gallery Entering the Hall of Chemistry
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Entering the Hall of Chemistry
The knowledge points of the first unit for eighth graders in the Lujiao version, including how amazing chemistry is, Experience chemical exploration, basic skills training in chemical experiments, etc.
Edited at 2024-02-03 12:06:46
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- Outline
Entering the Hall of Chemistry
Chemistry is amazing
Research object
substance
Research methods
experiment
research content
Study the causes and laws of matter and its changes
Research purposes
Change and create matter and obtain energy
field of chemical action
information Science
Development of functional materials
Energy development and utilization
environmental protection
life process exploration
How chemistry changes the world
cause chemical changes in substances
physical changes
There is no change in the creation of new matter, just a change in shape and state
Chemical changes
changes that create new substances
Observe the phenomenon of chemical changes
light magnesium bar
burning violently
emit dazzling white light
exothermic
Produces white powdery solid
Add a small amount of sodium hydroxide solution to the test tube Add a few more drops of phenolphthalein test solution
The solution changes from colorless to red
Put a few zinc particles into the test tube Then add 3~4mL dilute hydrochloric acid
A large number of bubbles are generated on the surface of zinc particles
solids reduction
exothermic
Take 3~4mL copper sulfate solution in a test tube Then add 4 to 5 drops of sodium hydroxide solution with a dropper
Produces blue flocculent precipitate
Basic characteristics of chemical changes
New substances are produced
chemical change phenomenon
Emit light, generate heat, change color, produce gas and form deposits
By observing these phenomena, infer whether chemical changes have occurred
energy changes
The release or absorption of thermal energy, light energy, and electrical energy,
material composition
Water is made up of water molecules
Water molecules are made up of hydrogen atoms and oxygen atoms
A water molecule is made up of two hydrogen atoms and one oxygen atom
Everything in the world is composed of extremely tiny particles (molecules, atoms, etc.)
Chemistry is a basic discipline that studies substances and their changing laws at the atomic and molecular level. It can guide us to better understand, transform and apply matter
Composition, structure→properties→applications
microscopic composition of matter
Silicon is made of silicon atoms
Iron is made of iron atoms
Carbon monoxide is made up of carbon monoxide molecules
Experience chemistry exploration
How to carry out chemical scientific research?
start with questions
Solving problems through scientific inquiry
Reflect on inquiry activities
Basic aspects of scientific inquiry
Ask a question
Conjectures and Assumptions
collect evidence
reach conclusion
Reflection and Evaluation
expression and communication
Basic skills training for chemical experiments
Chemistry Laboratory Safety Rules
Three mistakes in the experiment
Do not touch the medicine with your hands
Do not put your nostrils to the mouth of the container to smell the smell of the medicine
Tasting of medicines is strictly prohibited
Three things to do after the experiment
Do not put the remaining medicines in the experiment back into the original bottles.
Don't throw it away casually
It cannot be taken out of the laboratory and must be placed in designated containers.
Taking medicines
Powdered solid medicine Block medicine
Use a medicine spoon or paper slot or tweezers
First lay the test tube flat
Then insert the spoon containing the medicine or the tweezers used to hold the solid into the test tube.
Hold the test tube upright so that the medicine slowly slides to the bottom of the test tube
liquid medicine
Remove the cork and place it upside down on the table
Pick up the bottle with your palm facing the label
Place the mouth of the bottle close to the mouth of the test tube, and slowly pour the liquid into the test tube.
When adding liquid into the test tube with a rubber-tipped dropper, The rubber dropper should hang above the mouth of the test tube and cannot touch the test tube.
Experimental phenomena
Sodium hydroxide solution Copper sulfate solution
blue flocculent precipitate
Sodium hydroxide solution phenolphthalein test solution
The solution changes from colorless to red
Copper sulfate solution phenolphthalein test solution
none
heating of matter
Heating liquid in test tube
The liquid volume must not exceed 1/3 of the test tube volume
The test tube clamp is held about 1/3 away from the test tube mouth
The test tube is tilted
Preheat the test tube first
During the heating process, the test tube should be moved up and down slightly.
Notice
Do not use hand-held test tubes to heat them, and do not touch the test tubes that have just been heated to avoid burns.
When heating, never point the mouth of the test tube toward yourself or others to prevent the liquid from boiling and splashing, causing injury.
Use of alcohol lamp
External flame heating
Cover the lamp cap to extinguish the alcohol lamp twice
Notice
Do not add alcohol to a burning alcohol lamp
Do not use a burning alcohol lamp to light another alcohol lamp
The amount of alcohol in the alcohol lamp is average, 1/3 to 2/3 of the volume of the alcohol lamp.
Causes of rupture of liquid heating test tubes
There are water drops on the outer wall of the test tube
Not preheated
During the heating process, the bottom of the test tube touches the wick
After heating, rinse immediately with cold water
solid heating
The mouth of the test tube is slightly tilted downwards
Move the alcohol lamp back and forth
Causes of rupture of solid heating test tubes
There are water drops on the outer wall of the test tube
Not preheated
During the heating process, the bottom of the test tube touches the wick
After heating, rinse immediately with cold water
The mouth of the test tube is not tilted downwards