"Laboratory Preparation and Properties of Oxygen" Air Around Us PPT Courseware 5

"Laboratory Preparation and Properties of Oxygen" Air Around Us PPT Courseware 5

Purpose

1. Learn how to produce oxygen in the laboratory.

2. Deepen your understanding of the properties of oxygen.

Experimental supplies

1. Equipment

Large test tube, single-hole rubber stopper, rubber tube, glass tube, gas bottle, sink, iron stand (with iron clamp), alcohol lamp, glass piece, crucible tongs, thin wire, wooden strips, cotton, matches.

2. Medicines

Potassium permanganate, charcoal, clarified lime water.

Activity experience

1. Preparation of oxygen

(1) The experimental device is as shown in the figure:

A is a ________ device; B is a ________ device.

(2) Operation steps:

Check: Check the air tightness of the device. The specific operation is ____________________________. If bubbles appear, install _______.

Loading: Put the medicine into the test tube. A ball of cotton should be stuffed into the mouth of the test tube for the purpose of __________________.

Fix: Plug the mouth of the test tube tightly with a rubber stopper with a conduit, and fix the mouth of the test tube on the iron stand.

Point: Fill the gas bottle with water and place it together with the glass piece in the sink. Light the alcohol lamp to heat. The test tube is heated _____ first, then ________.

Collect: Start collecting when ______________. When the water in the gas collecting bottle is drained, cover the mouth of the bottle with a glass piece under the water surface, move the bottle out of the sink, and _____ on the table.

Away: Remove the air pipe from the sink.

Extinguish: Extinguish the alcohol lamp.

In the process of producing oxygen:

(1) When using the drainage method to collect gas, collect it immediately when you observe bubbles emerging from the tube. Is this correct? Why?

Tip: Incorrect. Because the bubbles that initially emerge from the tube are not pure gas, but the original air in the experimental device or a mixture of air and produced gas, you should wait until the bubbles emerge continuously and evenly to collect them.

(2) When using the drainage method to collect oxygen, how to prove that the oxygen has been fully collected?

Tip: If you use the drainage method to collect oxygen, when you see big bubbles coming out of the mouth of the gas collecting bottle, it proves that the collection is full.

(3) When using potassium permanganate (or potassium chlorate) to produce oxygen, why do you need to withdraw the catheter first and then stop heating?

Tip: Since potassium permanganate (or potassium chlorate) is used to produce oxygen, it needs to be heated with an alcohol lamp. If the heating is stopped at the end of the experiment and then the tube is withdrawn, the pressure in the test tube will become smaller due to the cooling of the test tube, and the water will be poured out. It may be sucked into the test tube and cause the test tube to burst. Therefore, the tube should be withdrawn first and then the alcohol lamp should be extinguished.

Experimental drill

1. Potassium permanganate is used to produce oxygen in the laboratory. After collection, the correct sequence for disassembling the device is ()

①Remove the alcohol lamp ②Take out the catheter from the sink

③Remove the test tube from the iron stand

A.①③②B.③②①

C.②①③ D.①②③

[Analysis] Choose C. After the collection is completed, the correct sequence for disassembling the device is: take out the catheter from the sink, remove the alcohol lamp, and remove the test tube from the iron stand.

2. A classmate used potassium permanganate as raw material to produce oxygen and collected it using the drainage method. However, the oxygen was not collected after heating for a long period of time. The possible reason is ()

A. Too little potassium permanganate B. No cotton added to the test tube mouth

C. The air tightness of the device is not good D. The heating temperature is not high

[Analysis] Choose C. If no oxygen is collected after heating for a long period of time, it means that the device is leaking, that is, the air tightness of the device is not good.

3. In the device for producing oxygen with potassium permanganate in the laboratory, which statement about several "mouths" is wrong ()

A. The opening of the test tube containing drugs should be upward

B. The opening of the air guide tube entering the test tube should expose a little of the single-hole plug.

C. When using the exhaust method to collect oxygen, the mouth of the gas collecting bottle should be facing upward.

D. When using the upward air exhaust method to collect oxygen, the mouth of the air guide should be extended into the bottom of the gas collecting bottle

[Analysis] Choose A. The mouth of the test tube should be tilted slightly downward to prevent condensed water from flowing back into the test tube and causing the test tube to burst.

8. Write down the reasons for the following experimental situations:

(1) Stretch the iron wire into a gas bottle containing oxygen and burn it. At the end of the experiment, it was found that the bottom of the gas bottle burst: ____________.

(2) When doing an experiment on burning charcoal in oxygen, the charcoal went out quickly after being put into the gas collecting bottle:___________.

(3) When potassium permanganate is added to the test tube, the drug adheres to the inner wall of the test tube and is not concentrated at the bottom of the test tube: _____________.

(4) When checking the air tightness of the device, there are no bubbles emerging from the pipe mouth immersed in water: ____________.

(5) When potassium permanganate is used to produce oxygen, the water in the sink turns purple: ______.

[Analysis] (1) Iron wire is burned in a gas bottle filled with oxygen. In order to prevent the generated melt from exploding the bottom of the bottle, spread a layer of fine sand or pour a small amount of water at the bottom of the bottle; (2) Charcoal is placed in the oxygen bottle. The reason why the combustion is extinguished quickly: the charcoal does not extend slowly from top to bottom, causing the heat released by the burning of the charcoal to cause the oxygen to expand and be discharged; (3) When taking powdered solid medicine, the test tube must be placed horizontally first, and then use a medicine spoon or Put the medicine into the bottom of the test tube through the paper trough, and then stand the test tube up, otherwise the medicine will adhere to the inner wall of the test tube and not be concentrated at the bottom of the test tube; (4) The reason why there are no bubbles at the mouth of the catheter is: it may be that the hand was inserted into the mouth of the catheter before it was inserted into the water. The test tube has already been held or the holding time may be too short; (5) Heat potassium permanganate to produce oxygen and collect it using the drainage method. In order to prevent potassium permanganate from entering the sink along the conduit, a ball of cotton should be placed at the mouth of the test tube and the sink The water turns purple, indicating that there is no cotton stuffed in the mouth of the test tube.

Keywords: The air around us teaching courseware, the laboratory preparation and properties of oxygen teaching courseware, the People's Education Press version of the ninth grade chemistry PPT courseware download, the ninth grade chemistry slide courseware download, the air around us PPT courseware download, oxygen Laboratory preparation and properties PPT courseware download, .PPT format;

For more information about "Laboratory Preparation and Properties of Oxygen in the Air Around Us" PPT courseware, please click on the "Laboratory Preparation and Properties of Oxygen in the Air Around Us" ppt tag.

"Laboratory Preparation and Properties of Oxygen" PPT Courseware 4:

"Laboratory Preparation and Properties of Oxygen" PPT Courseware 4 Experimental Purpose 1. Learn the method of producing oxygen in the laboratory. 2. Deepen your understanding of the properties of oxygen. Experimental supplies 1. Equipment: large test tube, single-hole rubber stopper, rubber tube, glass tube, gas bottle, sink, iron frame...

"Laboratory Preparation and Properties of Oxygen" PPT Courseware 3:

"Laboratory Preparation and Properties of Oxygen" PPT courseware 3 1. Producing oxygen by heating potassium permanganate 1. Experiment purpose: Preparing oxygen and exploring the properties of oxygen 2. Experimental principle: 3. Instruments and medicines: iron stand, Iron clamps, test tubes, single-hole rubber stoppers, air tubes, collection...

"Laboratory Preparation and Properties of Oxygen" PPT Courseware 2:

"Laboratory Preparation and Properties of Oxygen" PPT Courseware 2 Learning Objectives 1. Practice the method of producing and collecting oxygen in the laboratory. 2. Verify the chemical properties of oxygen by burning charcoal and iron wire. Pre-study tutorial 1. Prepare experimental instruments and drugs, iron stand (with iron clamps), test tubes...