1. Chapter 5 Properties of Matters CHEMISTRY - DACS 1232
Fakulti Kejuruteraan Mekanikal, UTeM
Lecturer:
IMRAN SYAKIR BIN MOHAMAD
MOHD HAIZAL BIN MOHD HUSIN
NONA MERRY MERPATI MITAN
Properties of Matters
Chapter 5

2. Three States of Matter

3. Phase Changes
Phase changes, trans-formations from one phase to another, occur when energy (usually in the form of heat) is added or removed.
3 Phases
H2O (l) H2O (g)
Gas phase - steam
Liquid phase - water
H2O (s) H2O (l)
Solid phase - ice
H2O (s) H2O (g)

4. Phase Changes Melting solid  liquid Freezing liquid  solid
Condensation
Evaporation
Freezing liquid  solid
Vaporization liquid  gas
Deposition
Sublimation
Condensation gas  liquid
Sublimation solid  gas
Melting
Freezing
Deposition gas  solid

6. Phase Diagram of Water
A phase diagram summarizes the conditions at which a substance exists as a solid, liquid, or gas.

7. Physical Characteristics of Gases
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.

8. Elements that exist as gases at 25 0C and 1 atmosphere

10. Force Pressure = Area Units of Pressure 1 pascal (Pa) = 1 N/m2
Barometer
Units of Pressure
1 pascal (Pa) = 1 N/m2
1 atm = 760 mmHg = 760 torr
1 atm = 101,325 Pa

11. 10 miles
0.2 atm
4 miles
0.5 atm
Sea level
1 atm

12. As P (h) increases
V decreases

13. Boyle’s Law P a 1/V P x V = constant P1 x V1 = P2 x V2
Constant temperature
Constant amount of gas
P x V = constant
P1 x V1 = P2 x V2

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. Scuba Diving and the Gas Laws
Chemistry in Action:
Scuba Diving and the Gas Laws
Depth (ft)
Pressure (atm) 1 33 2 66 3 P V

16. Charles’ & Gay-Lussac’s Law
As T increases
V increases

17. V a T V = constant x T V1/T1 = V2/T2
Variation of gas volume with temperature at constant pressure.
V a T
Temperature must be
in Kelvin
V = constant x T
V1/T1 = V2/T2
T (K) = t (0C)

18. A sample of carbon monoxide gas occupies 3. 20 L at 125 0C
A sample of carbon monoxide gas occupies 3.20 L at 125 0C. At what temperature will the gas occupy a volume of 1.54 L if the pressure remains constant?

19. Avogadro’s Law V a number of moles (n) V = constant x n V1/n1 = V2/n2
Constant temperature
Constant pressure
V a number of moles (n)
V = constant x n
V1/n1 = V2/n2

20. Ammonia burns in oxygen to form nitric oxide (NO) and water vapor
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 Boyle’s law: V a (at constant n and T) 1 P
Charles’ law: V a T (at constant n and P)
Avogadro’s law: V a n (at constant P and T)
V a nT P
V = constant x = R nT P
R is the gas constant
PV = nRT

22. PV = nRT PV R = nT (1 atm)(22.4L) = (1 mol)(273.15 K)
The conditions 0 0C and 1 atm are called standard temperature and pressure (STP).
Experiments show that at STP, 1 mole of an ideal gas occupies 22.4 L.
PV = nRT
R = PV nT =
(1 atm)(22.4L)
(1 mol)( K)
R = L • atm / (mol • K)

23. What is the volume (in liters) occupied by 49.8 g of HCl at STP?

24. d is the density of the gas in g/L
Density (d) Calculations
d = m V PM RT
m is the mass of the gas in g
M is the molar mass of the gas
PV = nRT
= RT M
PM = RT
= dRT
Molar Mass (M ) of a Gaseous Substance
dRT P
M =
d is the density of the gas in g/L

25. C6H12O6 (s) + 6O2 (g) 6CO2 (g) + 6H2O (l)
Gas Stoichiometry
What is the volume of CO2 produced at 370 C and 1.00 atm when 5.60 g of glucose are used up in the reaction:
C6H12O6 (s) + 6O2 (g) CO2 (g) + 6H2O (l)

26. Strong intermolecular forces
Liquids
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

27. Cohesion is the intermolecular attraction between like molecules
Adhesion is an attraction between unlike molecules
Adhesion
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.
Cohesion
water
mercury

28. Viscosity is a measure of a fluid’s resistance to flow.
Strong intermolecular forces
High viscosity

29. Unit cells in 3 dimensions
Solids
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.
lattice
point
Unit Cell
Unit cells in 3 dimensions

34. Shared by 8 unit cells
Shared by 2 unit cells

35. 1 atom/unit cell
2 atoms/unit cell
4 atoms/unit cell
(8 x 1/8 = 1)
(8 x 1/8 + 1 = 2)
(8 x 1/8 + 6 x 1/2 = 4)

37. When silver crystallizes, it forms face-centered cubic cells
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 sinq
= nl
(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
CsCl
ZnS
CaF2

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
carbon
atoms
diamond
graphite

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. Cross Section of a Metallic Crystal
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-

45. Types of Crystals