Presentation on theme: "1 Properties of Matters Chapter 5 CHEMISTRY - DACS 1232 Fakulti Kejuruteraan Mekanikal, UTeM Lecturer: IMRAN SYAKIR BIN MOHAMAD MOHD HAIZAL BIN MOHD HUSIN."— Presentation transcript:
1 Properties of Matters Chapter 5 CHEMISTRY - DACS 1232 Fakulti Kejuruteraan Mekanikal, UTeM Lecturer: IMRAN SYAKIR BIN MOHAMAD MOHD HAIZAL BIN MOHD HUSIN NONA MERRY MERPATI MITAN
2 Three States of Matter
3 3 Phases Solid phase - ice Liquid phase - water Phase Changes Phase changes, trans-formations from one phase to another, occur when energy (usually in the form of heat) is added or removed. Gas phase - steam H 2 O (l) H 2 O (g) H 2 O (s) H 2 O (l) H 2 O (s) H 2 O (g)
4 Evaporation Condensation Melting Freezing Sublimation Deposition Phase Changes Melting solid liquid Freezing liquid solid Vaporization liquid gas Condensation gas liquid Sublimation solid gas Deposition gas solid
6 A phase diagram summarizes the conditions at which a substance exists as a solid, liquid, or gas. Phase Diagram of Water
7 Gases assume the volume and shape of their containers. Gases are the most compressible state of matter. Gases will mix evenly and completely when confined to the same container. Gases have much lower densities than liquids and solids. Physical Characteristics of Gases Gases
8 Elements that exist as gases at 25 0 C and 1 atmosphere
10 Units of Pressure 1 pascal (Pa) = 1 N/m 2 1 atm = 760 mmHg = 760 torr 1 atm = 101,325 Pa Barometer Pressure = Force Area
13 P 1/V P x V = constant P 1 x V 1 = P 2 x V 2 Boyle’s Law Constant temperature Constant amount of gas
14 A sample of chlorine gas occupies a volume of 946 mL at a pressure of 726 mmHg. What is the pressure of the gas (in mmHg) if the volume is reduced at constant temperature to 154 mL?
15 Chemistry in Action: Scuba Diving and the Gas Laws PV Depth (ft) Pressure (atm)
16 As T increasesV increases Charles’ & Gay-Lussac’s Law
17 Variation of gas volume with temperature at constant pressure. V TV T V = constant x T V 1 /T 1 = V 2 /T 2 T (K) = t ( 0 C) Temperature must be in Kelvin
18 A sample of carbon monoxide gas occupies 3.20 L at C. At what temperature will the gas occupy a volume of 1.54 L if the pressure remains constant?
19 Avogadro’s Law V number of moles (n) V = constant x n V 1 /n 1 = V 2 /n 2 Constant temperature Constant pressure
20 Ammonia burns in oxygen to form nitric oxide (NO) and water vapor. How many volumes of NO are obtained from one volume of ammonia at the same temperature and pressure?
21 Ideal Gas Equation Charles’ law: V T (at constant n and P) Avogadro’s law: V n (at constant P and T) Boyle’s law: V (at constant n and T) 1 P V V nT P V = constant x = R nT P P R is the gas constant PV = nRT
22 The conditions 0 0 C and 1 atm are called standard temperature and pressure (STP). PV = nRT R = PV nT = (1 atm)(22.4L) (1 mol)( K) R = L atm / (mol K) Experiments show that at STP, 1 mole of an ideal gas occupies 22.4 L.
23 What is the volume (in liters) occupied by 49.8 g of HCl at STP?
24 Molar Mass ( M ) of a Gaseous Substance dRT P M = d is the density of the gas in g/L Density (d) Calculations d = m V PMPM RT m is the mass of the gas in g M is the molar mass of the gas PV = nRT = RT m M P M = RT m V = dRT
25 Gas Stoichiometry What is the volume of CO 2 produced at 37 0 C and 1.00 atm when 5.60 g of glucose are used up in the reaction: C 6 H 12 O 6 (s) + 6O 2 (g) 6CO 2 (g) + 6H 2 O (l)
26 Properties of Liquids Surface tension is the amount of energy required to stretch or increase the surface of a liquid by a unit area. Strong intermolecular forces High surface tension Liquids
27 Cohesion is the intermolecular attraction between like molecules Adhesion is an attraction between unlike molecules Adhesion Cohesion When adhesion is greater than cohesion, the liquid rises in the capillary tube. When cohesion is greater than adhesion, a depression of the liquid in the capillary tube. watermercury
28 Viscosity is a measure of a fluid’s resistance to flow. Strong intermolecular forces High viscosity
29 A crystalline solid possesses rigid and long-range order. In a crystalline solid, atoms, molecules or ions occupy specific (predictable) positions. An amorphous solid does not possess a well-defined arrangement and long-range molecular order. A unit cell is the basic repeating structural unit of a crystalline solid. Unit Cell lattice point Unit cells in 3 dimensions Solids
34 Shared by 8 unit cells Shared by 2 unit cells
35 1 atom/unit cell (8 x 1/8 = 1) 2 atoms/unit cell (8 x 1/8 + 1 = 2) 4 atoms/unit cell (8 x 1/8 + 6 x 1/2 = 4)
37 When silver crystallizes, it forms face-centered cubic cells. The unit cell edge length is 409 pm. Calculate the density of silver.
39 Extra distance = BC + CD = 2d sin = n (Bragg Equation)
40 X rays of wavelength nm are diffracted from a crystal at an angle of Assuming that n = 1, what is the distance (in pm) between layers in the crystal?
41 Types of Crystals Ionic Crystals Lattice points occupied by cations and anions Held together by electrostatic attraction Hard, brittle, high melting point Poor conductor of heat and electricity CsClZnSCaF 2
42 Types of Crystals Covalent Crystals Lattice points occupied by atoms Held together by covalent bonds Hard, high melting point Poor conductor of heat and electricity diamond graphite carbon atoms
43 Types of Crystals Molecular Crystals Lattice points occupied by molecules Held together by intermolecular forces Soft, low melting point Poor conductor of heat and electricity
44 Types of Crystals Metallic Crystals Lattice points occupied by metal atoms Held together by metallic bonds Soft to hard, low to high melting point Good conductors of heat and electricity Cross Section of a Metallic Crystal nucleus & inner shell e - mobile “sea” of e -