WUJUD ZAT Oleh A. Sjaifullah

Kimia adalah Pengetahuan yang mempelajari materi dan perubahannya Materi adalah Apapaun yang memiliki massa dan menempati ruang

Teori Kinetik Semua partikel (atoms, molekul dan ion) menyusun materi selalu bergerak secara random dan berinteraksi

WujudWujud zat Wujud  Cara menyusun partikel  Energi partikel  Interaksi/jarak antar partikel

Karakteristik wujud zat wujud Sifat partikel ProximityEnergygerakanVolumebentuk padat cair gas closelittlevibrationaldefinite closemoderaterotationaldefiniteindefinite far aparta lottranslationalindefinite

Jika kondisi partikel (susunan, interaksi dan energi) diubah, maka terjadi perubahan wujudperubahan Perubahan wujud terjadi dalam siklus air di alamsiklus posisi partikel-partikel zat cair & gas tidak tetap, Zat cair dan gas dapat dialirkan/berdifusi =(fluida)

Salah satu sifat gas adalah dapat memberikan tekanan. Sifat-sifatSifat-sifat gas Tekanan yang disebabkan oleh campuran gas-gas yang ada di udara disebut tekanan atmosfir Tekanan gas terjadi akbat dari tumbukan partikel- partikel gas dengan dindingtumbukan Tekanan adalah…..

Mengapa tekanan udara sangat penting? · Adanya angin · Menciptakan mendung dan awan

Hubungan tekanan dan volume gas Hukum Boyle P 1 V 1 = P 2 V 2

Volume and Temperature, tekanan tetap Hukum Charles V1V1 T1T1 V2V2 T2T2 =

Korek gas, hair spray, tabung LPG akan terasa lebih dingin jika digunakan, Karena……………..

Karena partikel gas hampir tidak berinteraksi satu sama lain, jumlah partikel (molekul) gas hanya bisa ditentukan/diukur pada volume, tekanan dan suhu tertentu

Persamaan keadaan gas ideal.

Volume molar gas pada STP

Zat Cair

Properties of Liquids Surface tension: the energy required to increase the surface area of a liquid by a unit amount. Viscosity: a measure of a liquid’s resistance to flow.

Tekanan Uap Cairan

ZAT PADAT Karena interaksi yang kuat, posisi partikel-partikel dalam zat padat tidak berubah terhadap satu dengan yang lain Amorf Kristal

Comparison: Amorphous solids Tar, molten glass, molten plastics, and molten butter, consist of large molecules or a mixture of molecules that cannot move readily. As the temperature is lowered, their molecules move more and more slowly and finally stop in random positions. The resulting materials are called amorphous solids or glasses. Such solids lack an ordered internal structure. Common examples include candle wax, butter, glass, and plastics.

Crystals are classified into systems based on the angle their bonds form. *7 common systems Isometric, Hexagonal, Tetragonal, Trigonal, Triclinic, Monoclinic, Orthorhombic

What crystal system does this mineral belong to? Why? Quartz Hexagonal 3 equilateral axes intersect at angels of 60 o, 1 vertical axis intersect at 90 o to equilateral axes. Hexa-six Beryl

What crystal system does this mineral belong to? Why? MONOCLINIC 3 unequal axes and 1 unequal intersection that is not at 90 o Mono-one GYPSUM

What crystal system does this mineral belong to? Why? Isometric 3 axes are at right angles, all sides equal length. Iso- same Sugar

What crystal system does this mineral belong to? Why? Tetragonal 3 axes are at right angels, only 2 lateral axes are equal length and it has 4 sides. Tetra-four WULFENITE

What crystal system does this mineral belong to? Why? ORTHORHOMBIC 3 unequal axes all at right angles to each other Ortho-unequal TANZANITE

What crystal system does this mineral belong to? Why? Trigonal 3 equal length axes, 3 equal intersections (not 90 o ) Tri- three Amazonite Note: Hexagonal but with 3 sides not 6

What crystal system does this mineral belong to? Why? Triclinic 3 unequal axes and 3 unequal intersections not at 90 o Tri-three

Using your 3-D structures identify the following into rightful system: Picture 1 Isometric Picture 2 Tetragonal Picture 3 Hexagonal Picture 4 Trigonal Picture 5 ORTHORHOMBIC Picture 6 MONOCLINIC Picture 7 TRICLINIC

Crystal Systems SystemAxesAnglesUnique SymmetryDiagramExamples Isometric a=b=c  =  =  =90° Four 3-foldPyrite, Halite, Galena, Garnet, Diamond, Fluorite Tetragonal a=b  c  =  =  =90° One 4-foldWulfenite, Rutile, Zircon, Chalcopyrite Hexagonal a=b  c  =120°,  =  =90° One 6-foldQuartz, Beryl (Emerald), Apatite, Corundum (Ruby, Sapphire) Orthorhombic a  b  c  =  =  =90° Three 2-foldSulfur, Barite, Olivine, Topaz Monoclinic a  b  c  =  =90°,  90° One 2-foldOrthoclase, Malachite, Azurite, Mica, Gypsum, Talc Triclinic a  b  c  90° NoneTurquoise, Kyanite, Albite, Plagioclase

Crystal Systems SystemAxesAnglesUnique SymmetryDiagramExamples Isometric Tetragonal Hexagonal Orthorhombic Monoclinic Triclinic

Struktur NaCl STRUCTURE OF OTHER SYSTEMS

SOME DEFINITIONS … Lattice: 3D array of regularly spaced points Crystalline material: atoms situated in a repeating 3D periodic array over large atomic distances Amorphous material: material with no such order Hard sphere representation: atoms denoted by hard, touching spheres Reduced sphere representation Unit cell: basic building block unit (such as a flooring tile) that repeats in space to create the crystal structure; it is usually a parallelepiped or prizm

Cubic unit cell is 3D repeat unit Rare (only Po has this structure) Close-packed directions (directions along which atoms touch each other) are cube edges. Coordination # = 6 (# nearest neighbors) (Courtesy P.M. Anderson) SIMPLE CUBIC STRUCTURE (SC)

ATOMIC PACKING FACTOR Fill a box with hard spheres –Packing factor = total volume of spheres in box / volume of box –Question: what is the maximum packing factor you can expect? In crystalline materials: –Atomic packing factor = total volume of atoms in unit cell / volume of unit cell –(as unit cell repeats in space)

APF for a simple cubic structure = 0.52 ATOMIC PACKING FACTOR contains 8 x 1/8 = 1atom/unit cell Adapted from Fig. 3.19, Callister 6e. Lattice constant close-packed directions a R=0.5a

Coordination # = 8 Adapted from Fig. 3.2, Callister 6e. (Courtesy P.M. Anderson) Close packed directions are cube diagonals. --Note: All atoms are identical; the center atom is shaded differently only for ease of viewing. BODY CENTERED CUBIC STRUCTURE (BCC)

APF for a body-centered cubic structure =  3/8 = 0.68 Adapted from Fig. 3.2, Callister 6e. ATOMIC PACKING FACTOR: BCC

Coordination # = 12 Adapted from Fig. 3.1(a), Callister 6e. (Courtesy P.M. Anderson) Close packed directions are face diagonals. --Note: All atoms are identical; the face-centered atoms are shaded differently only for ease of viewing. FACE CENTERED CUBIC STRUCTURE (FCC)

APF for a body-centered cubic structure =  /(3  2) = 0.74 (best possible packing of identical spheres) Adapted from Fig. 3.1(a), Callister 6e. ATOMIC PACKING FACTOR: FCC

ABCABC... Stacking Sequence FCC Unit Cell FCC STACKING SEQUENCE 2D Projection

HEXAGONAL CLOSE-PACKED STRUCTURE (HCP) Ideally, c/a = for close packing However, in most metals, c/a ratio deviates from this value

Coordination # = 12 ABAB... Stacking Sequence APF = 0.74, for ideal c/a ratio of D Projection 2D Projection Adapted from Fig. 3.3, Callister 6e. HEXAGONAL CLOSE-PACKED STRUCTURE (HCP)

STATES OF MATTER The Four States of Matter The Four States of Matter Four States Four States Solid Solid Liquid Liquid Gas Gas Plasma Plasma

Kinetic Theory of Matter Matter is made up of particles which are in continual random motion.

STATES OF MATTER SOLIDS Particles of solids are tightly packed, vibrating about a fixed position. Solids have a definite shape and a definite volume. Heat

STATES OF MATTER LIQUID  Particles of liquids are tightly packed, but are far enough apart to slide over one another.  Liquids have an indefinite shape and a definite volume. Heat

STATES OF MATTER GAS  Particles of gases are very far apart and move freely.  Gases have an indefinite shape and an indefinite volume. Heat

PHASE CHANGES Description of Phase Change Term for Phase Change Heat Movement During Phase Change Solid to liquid Melting Heat goes into the solid as it melts. Liquid to solid Freezing Heat leaves the liquid as it freezes.

PHASE CHANGES Description of Phase Change Term for Phase Change Heat Movement During Phase Change Liquid to gas Vaporization, which includes boiling and evaporation Heat goes into the liquid as it vaporizes. Gas to liquidCondensation Heat leaves the gas as it condenses. Solid to gasSublimation Heat goes into the solid as it sublimates.

STATES OF MATTER PLASMA  A plasma is an ionized gas.  A plasma is a very good conductor of electricity and is affected by magnetic fields.  Plasmas, like gases have an indefinite shape and an indefinite volume. Plasma is the common state of matter

STATES OF MATTER SOLID LIQUID GAS PLASMA Tightly packed, in a regular pattern Vibrate, but do not move from place to place Close together with no regular arrangement. Vibrate, move about, and slide past each other Well separated with no regular arrangement. Vibrate and move freely at high speeds Has no definite volume or shape and is composed of electrical charged particles

Some places where plasmas are found… 1. Flames

2. Lightning

3. Aurora (Northern Lights)

The Sun is an example of a star in its plasma state

COLD PLASMA

COLD PLASMA PEN