Grade: Senior
Subject: Science

#2963. Chemistry

Science, level: Senior
Posted Mon Oct 27 19:47:26 PST 2003 by gursoy karatas (

Private Moldovian-Turkish High Schools, Cheadir-Lunga, Moldova

Lesson : Chemistry
Class : 10A
Date :
Duration : 45 min.
Unit : Gases
Topic : An introduction to gases
Aim : To learn general properties of gases
• What is gas?
• Common Properties of gases
• How can we determine properties of gases?
Matter is anything that has a mass and occupies space. There are three (fourth; plasma) states of matter; gaseous, liquid and solid. Today we are going to study gaseous state of matter.
• Gases are the cluster of particles.
• They move with a very fast speed.
• Their motions are freely and randomly, not regularly. The molecules of gases are relatively far away each other. So, the effect of a molecule is very small and it can be neglected. But solids and liquids are different.
• Gases have neither definite shape nor volume. Their shapes are the shapes of their containers. Like liquids, gases take the shape of their containers. And their volumes are the volume of the container.
• Gases are more compressible than liquids and solids since big distances between molecules of gases.
1,5 gram of oxygen gas occupies 1050 ml volume, same amount of liquid and solid of oxygen occupies 1,3 ml and 1 ml volume, respectively.
• Molecules of gases diffuse each other. When a gas, such as perfume, is compressed in a room, its molecules diffuse throughout the room and the smell of the gas can be felt in every part of the room.
• Some gases are colored, such as chlorine, bromine, iodine
• Some gases are combustible, such as hydrogen, methane, CH4
• Some gases are uncreative such as helium and neon. (sun)
• Physical properties of gases can be determined by four quantities. These are;
- Pressure
- Volume
- Temperature
- Amount
If we know any three of these, we usually calculate a value of remaining one.

Homework: Search that how can we measure the pressure of a gas?
What are the differences between the gas state of mater and the liquid, solid state of mater?