Chapter 1 - Gaseous State PDF
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Uploaded by IntuitiveMesa
Faculty of Science Ain Shams
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Summary
This chapter describes the gaseous state of matter, differentiating between ideal and real gases. It details the properties of each type and how to measure their state using key variables like volume, amount, temperature, and pressure.
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## **Chapter 1 - Gaseous State** ### **The States of Matter** * Matter: Anything that has mass and occupies space. * Matter consists of very small particles called molecules. * The molecules tend to fly apart because of their kinetic energy. * There are attraction forces among molecules called "Va...
## **Chapter 1 - Gaseous State** ### **The States of Matter** * Matter: Anything that has mass and occupies space. * Matter consists of very small particles called molecules. * The molecules tend to fly apart because of their kinetic energy. * There are attraction forces among molecules called "Vander Waals Forces". * Accordingly the matter could be gas, liquid, or solid. ### **The Gaseous State** | State | Description | |---|---| | Ideal Gas | - Obeys the gas laws (Charles & Boyle's) at all T and P. - Volume of gas molecules is very small and can be neglected compared to the volume of the container. - There are no attraction or repulsion forces among the gas molecules. | | Real Gas | - Obeys the gas law at low (P) and high (T). - Volume of gas molecules can't be neglected. - The molecules of real gas exert some attractive and repulsion forces on each others. | The gas behaves ideally when the (T) is very high and (P) is very low. ### **Describing the State of Gaseous Substances** To completely describe the state of a gaseous substance, four quantities are needed: 1. **Volume (V)** * L, cm<sup>3</sup> * A gas expands uniformly to fill any container in which it is placed. * Volume of gas = volume of its container. 2. **Amount** * We can express the amount by its number of moles (n) and the mass in grams (M). * m = M × n 3. **Temperature (T)** * T<sub>R</sub> = [C] + 273.15 * [C] = ([T<sub>R</sub>] - 32) × 5/9 4. **Pressure (P)** * 1 atm = 76 cmHg = 760 mmHg = 1,013,961 dyne/cm<sup>2</sup> = 1.03 × 10<sup>5</sup> N/m<sup>2</sup> or Pa (Pascal).
