Unit 1 States of Matter chemistry IGCSE help
- 2. Unit 1 States of Matter ⦿ States of matter ⦿ Kinetic theory of matter ⦿ Heating and cooling curve ⦿ Diffusion
- 3. Objective – Class 1 ⦿ States of matter – Preknowledge ⦿ Kinetic theory of matter ⦿ Change of state of matter in terms of kinetic theory ⦿ Temperature curve
- 4. Preknowledge - matter and its states ⦿ Matter can be defined as: ⦿ States of matter ⦿ Composition of matter ⦿ Which state of matter fills the entire volume of container ⦿ Are all things matter?
- 5. Properties of Solid, liquids, and gases
- 6. Particle theory of matter ⦿ All matter is made up of small particles (atoms, molecules) ⦿ The particles are arranged differently in the three states of matter ⦿ The particles have different type of motion in different states ( Solids - vibrate, liquid - slide past one another, gas - move randomly in all directions. Particles are always in motion and not all particles have same energy and speed ⦿ The particles have force of attraction between them, which is strong when particles are close each other ⦿ There is space between particles (Solids - least, gas - maximum ) ⦿ The pressure of the gas due to the atoms or molecules of gas hitting the walls of the container.
- 8. Closely & orderly packed (Lattice) Loosely packed, can slide over Random, move in all direction Arrangemen t Movement Force of Attraction Space in between Very small Vibrates on its own axis Very strong Move slowly, slide over one another Weak Larger compared to solids Extremely weak and moves freely Move fast in all direction Very large space Particles solid Liquid Gas
- 28. Pressure - Gas ⦿ The pressure exerted by gas is caused by the gas particles hitting the walls of the container the gas is in. ⦿ Gas compressed into smaller volume, the no. of particles hitting the container per sec increases, thus pressure increases. Increase in no. of collisions/sec causes increase in pressure ⦿ If temp of gas increases, gas particles have more energy and move faster, hence more collisions with the sides of container each sec and so gas will exert greater pressure
- 29. Diffusion ⦿ Diffusion ⦿ Dissolving crystals in water ⦿ Mixing gases ⦿ Brownian movement ⦿ Molecular mass and diffusion
- 30. Diffusion - Activity ⦿ Take 2 clear glass tumblers ⦿ Fill three-fourth glass 1 with hot water and glass 2 with cold water ⦿ Add a pinch of food color to both the glass ⦿ What do u observe?
- 31. Diffusion ⦿ The random mixing and moving of particles in liquids, gases ⦿ Diffusion is the process of a substance spreading out to evenly fill its container or environment. In a solution, a concentrated solute diffuses to spread evenly in its solvent. ... Diffusion occurs because the gas molecules are in continuous random motion. ⦿ Temperature and rate of diffusion
- 33. Dissolving crystals (potassium manganate in water
- 34. Mixing gases
- 35. Diffusion and molecular mass of gas ⦿ Different gases move with different speed. Speed of gases depend on their molecular mass – larger the molecular mass, lesser the speed of molecules and hence lower diffusion capacity ⦿ H2 gas will diffuse much faster than CO2 gas
- 36. NH3 + HCl NH4Cl
- 37. Brownian motion ⦿ The erratic random movement of microscopic particles in a fluid, as a result of continuous bombardment from molecules of the surrounding medium. ⦿ Pollen grains in water (Robert Brown)
- 38. ⦿ Brownian motion can be observed in a laboratory using smoke cell. i) In what situation was Brownian motion first observed? ii) In the smoke cell, what causes the random motion of the smoke particle?
- 44. Predicting the physical state ⦿ The state of substance at a given temperature can be predicted if its melting point and boiling point are known.