"Composition of Air" PPT courseware on the composition of air and matter

Description

"Composition of Air" PPT courseware on the composition of air and matter

think

1. What would our world look like if there was no air in the world we live in?

2. The air is all around you. Can you describe its physical properties?

3. Is air a single substance? What are its main components?

think about it

1: Air is colorless and odorless and difficult to detect. Can you use a simple experiment or give an example to illustrate that air does exist?

Answer: 1) An empty gas bottle is pressed down in a tank filled with water - the water in the gas bottle cannot rise to the top.

2) The empty gas bottle stands on its side in a water tank filled with water - bubbles appear.

3) Shake the flat, dense bag after opening it, and then seal it - squeeze it with both hands to feel pressure.

4) The fan is blowing towards the face, the leaves are moving - there is wind

5) Pump up the tire - let it rise

think about it

1. According to the experimental phenomenon, what are the properties of the remaining gas in the analysis bottle?

Answer: Cannot burn or support combustion; cannot be dissolved in water

2. Can the "large amount of white smoke" generated after the combustion of red phosphorus be called "large amount of white mist"?

Answer: No, smoke is solid particles; fog is small droplets.

6. The key to a successful experiment:

(1) The device cannot leak;

(2) Add a small amount of water to the gas collecting bottle (to prevent the high-temperature melt from exploding the bottom of the bottle)

(3) Red phosphorus should be excessive

(4) After igniting red phosphorus, immediately put it into the gas collecting bottle and tighten the stopper.

(5) After the red phosphorus cools, open the spring clip

Analysis and induction

Please discuss with your classmates to answer the following questions based on the observed experimental phenomena.

The reason why all the red phosphorus is not burned in the gas cylinder is __________.

After igniting red phosphorus, why do you need to quickly insert the burning key into the gas collecting bottle and tighten the rubber stopper?

After the red phosphorus is extinguished, why do we have to wait until the gas collection bottle cools to room temperature before opening the spring clamp?

2. Air is a precious resource:

1. The purpose of oxygen: It used to be called "nourishing Qi"

(1) Provide breathing (2) Support combustion

2. Properties and uses of nitrogen

physical properties

Colorless, odorless gas. Insoluble in water and low melting point. Density: 1.251g/L

chemical properties

Cannot burn Cannot support burning

3. Properties and uses of rare gases

(1) Rare gases are the general term for gases such as helium, neon, argon, krypton, and xenon.

(2) Rare gases are colorless, odorless, and very inactive chemically.

(3) Purpose: protective gas, electric light source laser technology, low temperature anesthesia

Class exercises

1. Which of the following substances is pure ( )

A A rare gas separated from the air

Part B frozen distilled water

C salt water

D 75% medicinal alcohol

2. Among the following groups of substances, the former is a pure substance and the latter is a mixture ( )

A. Nitrogen Distilled water B． iron ore salt water

C. Hydrogen CaCO3 D． carbon dioxide air

3. Which of the following water is a pure substance ( )

A mineral water B tap water C river water D ice-floating water

In order to measure the respiration of plants, a classmate designed an experiment.

(1) The function of lime water in bottle C is _________.

(2) In order to eliminate the interference of external factors on the experiment, device A was designed, and its purpose is to ____________.

When delivering oxygen to patients in the hospital, the device in the picture below is used. That is, about half a bottle of distilled water is filled in the device. Pipe A is connected to the cylinder that supplies oxygen, and pipe B is connected to the plastic pipe through which the patient inhales oxygen. This device may work here. The function is:

a. Observe whether there is oxygen output

b. Observe the speed and slowness of the oxygen output

c. Prevent leakage of oxygen cylinders

d. Moisturizing oxygen is beneficial to patients

e. Dust in the oxygen output from the cylinder can be washed

Which of these roles do you think is reasonable?

A. a b c d e B. a b d e

C. a b d D. a c d

practice

Answer questions as requested:

①Add a small amount of water to the gas collecting bottle ②Check the air tightness of the device ③Put enough red phosphorus into the burning key and tighten the water stop clamp ④Ignite the red phosphorus, put it into the gas collecting bottle and tighten the rubber stopper ⑤Wait for collection After the cylinder cools down, open the water-stop clamp.

(1) The text expression of the reaction in step ④ is_______________;

(2) The phenomenon observed after opening the water stop clamp in step ⑤ is ____________;

(3) The experiment concluded that the composition of air is ____________;

(4) The properties of the remaining gas in this experiment are ____________;

(5) After the experiment, the water in the gas collecting bottle is less than 1/5. The reason for the error may be ____________;

3. Air pollution and its prevention

1. Harmful substances in the air

Harmful gases: sulfur dioxide (SO2), carbon monoxide (CO), nitrogen dioxide (N02)

Smoke (respirable particulate matter)

2. Three major types of pollution

SO2, NO2, etc. → acid rain

Freon, etc.→Ozone Hole

Increased CO2 content →greenhouse effect

Keywords: teaching courseware on the composition of air substances, teaching courseware on the composition of air, Guangdong Education Edition ninth-grade chemistry PPT courseware download, ninth-grade chemistry slide courseware download, composition of air substances PPT courseware download, composition of air PPT courseware download, .PPT format;

For more information about the PPT courseware "Composition of Air Substances Composition of Air", please click the Composition of Air Substances ppt Composition of Air ppt tag.

"Composition of Air" PPT courseware on the composition of air and matter 2:

"Composition of Air" PPT courseware on the composition of air and matter 2. Question introduction: What are the components in the air? How to keep the air clean and fresh? Air is the backbone of life for humans and all animals and plants, and it is also an important natural resource. Scientists use scientific inquiry methods...

File Info

Update Time: 2024-07-03

This template belongs to Chemistry courseware Cantonese Education Edition Ninth Grade Chemistry Volume 1 industry PPT template

Preview