توزيع درجات المقرر (1080 كيم ) Final Theoretical أعمال فصلية Practical Exam HomeworkReportAttendance Midterm #2 Midterm # Time: on Mon., 8:00- 11:00 am, Room: 72 Midterm #1: due on week # 7 Midterm #2: due on week # 11 Office Hours: Sunday after 11:00, Thursday after 11:00 General Chemistry CHEM 1080

Topics will be covered States of Matter Periodic table Gases Liquid Solids Chemical Equilibrium Chemical Kinetics Solutions

CHAPTER # 1 STATES OF MATTER & PROPERTIES

STATES OF MATTER

Matter is anything that has mass and occupies space. Mass is a measure of the quantity of matter in a sample of any material. Matter STATES OF MATTER solidliquid gas

Solid state 1- Rigid and has definite shapes. 2- Solid is very hard to compress (very slight compressibility). 3- Intermolecular spaces are VERY SMALL 4- Attractive force between atoms is VERY BIG. 5- Dispersion is VERY SMALL

7- Dispersion is middle. 6- Attractive force between atoms is middle. 5- Intermolecular spaces are middle. 4- Liquids are very hard to compress. (slight compressability) 3- Expansion on Heating is slight. 1- A liquid flows and has the shape of its container. Liquid state

Gas state 1- Gases are much less dense than liquids and solids. 2- They occupy all parts of any vessel (dispersion is very big) 3- Expansion is infinite. 4- Gases are Very compressible. 5- Intermolecular spaces are Very Big. 6- Attractive force between atoms is very small. 7- Dispersion is Very Big.

PHASE CHANGES Sublimation is the conversion of a solid directly to a gas without passing through the liquid state; the reverse of that process is called deposition. The changes shown in blue are endothermic (absorb heat); those shown in red are exothermic (release heat). relatively fixed in position, but those in the liquid and gas can flow around each other. Physical changes that occur among the three states of matter.

A mixture is a combination of two or more substances where there is no reaction. A. Homogeneous: mixture has uniform properties throughout; like solutions where salts are soluble in solvent Ex. NaCl + H2O b- Heterogeneous: a mixture, which is not uniform throughout, substances are insoluble Ex. Oil + H 2 O Ex. Sand + H 2 O

I- Dalton ’ s Atomic Theory (1808) 1. Elements are composed of extremely small particles called atoms. All atoms of a given element are identical, having the same size, mass and chemical properties. The atoms of one element are different from the atoms of all other elements. Atoms, Molecules and Ions

2. A molecule is combination of two or more atoms held together by covalent bonds. H2H2 H2OH2ONH 3 CH 4 4. A diatomic molecule contains only two atoms

5. A polyatomic molecule contains more than two atoms.

mass p ~ mass n = 1840 x mass e –

An atom contains equal numbers of electrons and protons. Atomic number (Z) = number of protons in the nucleus. Mass number (A) = number of protons + number of neutrons. X A Z Mass Number Atomic Number Element Symbol Atom, Atomic number, and Mass number Atomic Number Element Symbol

Atomic mass unit (amu), which is defined as exactly 1/12 of the mass atom of carbon -12. atom. Atomic mass is the mass of an atom in “atomic mass unit” (amu) By definition: 1 atom 12 C “weighs” 12 amu On this scale 1 H = ~ 1 amu 16 O = ~ 16 amu

Moles Defined as a mass in grams equal to atomic mass of a substance contains x particle mol -1 1 mole contains x particles x is called Avogadro ’ s number.

One Mole of: C S Cu Fe Hg 3.2

1 mol = N A = x Avogadro’s number (N A ) Mole Calculations 1 mol 12 C atoms = x C atoms The mole (mol): 1 mol H 2 O molecules = x H 2 O molecules 1 mole NO - 3 ions = x NO 3 - ions.

Molar mass is the mass of 1 mole of in grams atoms 1 mole 12 C atoms = x atoms = g 1 12 C atom = amu 1 mole 12 C atoms = g 12 C For any element atomic mass (amu) = molar mass (grams) Defined as the mass in grams of 1 mole of atoms, ions, or molecules.

Calculate the number of sodium atoms in mol Na? 1 mol of Na = x atoms of Na x atoms of Na 1 mol of Na mol NaX ? atoms of Na mol Na x 6.02 x 1023 atoms Na = 7.22 x mol Na Do You Understand Molar Mass?

How many atoms are in g of potassium (K) ? 1 mol of K = g of K 1 mol of K = x atoms of K g K g K 8.49 x atoms of K x atoms of K39.10 g of K X ? atoms g of K x atoms of K =x

Molecular mass (or molecular weight) is the sum of the atomic masses (in amu) in a molecule. SO 2 1S32.07 amu 2O+ 2 x amu SO amu For any molecule molecular mass in amu = molar mass in grams 1 molecule of SO 2 weighs amu 1 mole of SO 2 weighs g

How to calculate molecular mass for a compound Ex. H 2 O Atomic masses H = 1, O = 16 Molecular mass of H 2 O = [ 1x2] +16 = 18 One mole of H 2 O = 18 gram H 2 O Ex. CO 2 Atomic masses C = 12, O = 16 Molecular mass of CO 2 = 12 +[16 x 2] = 44 One mole of CO 2 = 44 gram CO 2