PRK 1016

Chemistry 1

Prepared by: Abdul Al-Hafiz Ismail

LU1: Chemistry and Chemical Nomenclature

• Definition for element, compound, atom, molecule and ion

LU1: Chemistry and Chemical Nomenclature

• SI base unit and its equivalent– Mass kg (g, mg)

– Volume liter (m3, cm3,dm3)

• Common decimal prefixes– Kilo (103) centi (10-2) micro (10-6)

• Exponential notation

• Very important in unit conversion and dimensional analysis

LU1: Chemistry and Chemical Nomenclature

• Uncertainty in measurement (measuring cylinder, burette)

• Significant figures– All non-zero numbers are significant (eg: 0.123) – 3

significant figures– Zeros between non-zero numbers are significant (eg: 106) –

3 significant figures– Zeros to the right of the non-zero number and to the right of

the decimal point are significant (eg: 0.1060) – 4 significant figures

– Zeros before non-zero numbers are not significant (eg: 0.00000524) – 3 significant figures

LU1: Chemistry and Chemical Nomenclature

• Rounding off (based on decimal point or significant figures)

• Definition of precision and accuracy

• absolute error, relative error and relative accuracy.

LU1: Chemistry and Chemical Nomenclature

• Modern atomic model (understand proton, electron, nucleus, neutron)

• Atomic mass = no. of proton

• Mass num = no. of proton + neutrons

• No. of proton = no. of electron

• Definition of isotopes and some examples

• Definition and differences between RAM, RMM and RFM

LU1: Chemistry and Chemical Nomenclature

• Different parts of mass spectrometer and how it works

LU1: Chemistry and Chemical Nomenclature

• Interpreting mass spectra in term of:– Relative abundance of isotopes

• Determination of RAM

– Molecular fragments• Base peak

• Molecular ion peak

LU2: Stoichiometry

• Understand the relationship between moles, molar mass and molar volume

• Avogadro constant

• Room and standard

LU2: Stoichiometry

• Units of concentrations

LU2: Stoichiometry

• Preparations of molar/standard solution– Volumetric flask

• Preparations of a solution by dilution– m1v1 = m2v2

• Naming chemical compounds

– Remember the monatomic and polyatomic ion

LU2: Stoichiometry

• Empirical formula. Steps used to determine the empirical formula of a compound.

1. Write the mass or percentage of each element in thecompound.

2. Calculate the number of moles of each element in thecompound by dividing the mass or percentage of theelement by the relative atomic mass of the element.

3. Then, divide each number by the smallest number toobtain the simplest ratio.

4. Finally, write the empirical formula of the compoundbased on the ratio of the element.

LU2: Stoichiometry

• Molecular formula

1. Determine the relative formula mass of the empiricalformula.

2. Divide the relative molecular mass by this.

3. If there are the same, then the empirical formula and themolecular formula are the same.

4. If the result is more than 1, multiply the empiricalformula by the this factor to find the molecular formula.

• Molecular formula = n (empiricalformula)

LU2: Stoichiometry

• Molecular equation

• Ionic equation

• Ion-electron equation– Half-equation

• Calculating reactants and products (mass, volume)– Limiting reactant (find the mole for each reactant and

relate it with the product. Which is smaller, we consider as limiting reactant.)

LU2: Stoichiometry

• Definition of percentage yield– Theoretical Yield & Actual Yield

• Theoretical yield – calculated yield based on the balanced equation (100% yield)

• Actual yield always less than 100%

• Definition of atom economy

LU2: Stoichiometry

• Definition of oxidation and reduction reaction

• Assigning oxidation number

– The oxidation number of any uncombined element is 0.

– The oxidation number of an uncombined ion is the same as its charge.

– The sum of all the oxidation numbers of a compound is 0.

– The sum of the oxidation numbers of all atoms in an ion is equal to thecharge on the ion.

– Group 1 elements always have oxidation number of +1, group 2 alwayshave +2 and group 13 always have +3.

– The more electronegative element in a substance is given a negativeoxidation number.

– The less electronegative one is given a positive oxidation number.

LU2: Stoichiometry

• Ionic half-equations for:– Oxidation: X X+ + e-

– Reduction: Y+ + e- Y

• Balancing redox equation– Acidic

– Basic

LU3: Structure of atoms

• Development of atomic model– Dalton’s atomic theory, Thomson’s Plum Pudding model

and Rutherford’s atom with a nucleus theory

• Electromagnetic waves (UV, visible, Infrared) electromagnetic spectrum

LU3: Structure of atoms

• Frequency (f) is inversely proportional towavelength ()

• Electromagnetic radiation has a dual"personality." Besides acting like waves, it actslike a stream of particles called "photons“

c f or

1 f =

E = h f

where E = energy in joule

h = Planck constant, which has the value 6.63

x 1034 J s

LU3: Structure of atoms

• A number of lines, each corresponding to a particular wavelength. This spectrum is called line spectrum.

LU3: Structure of atoms

c f or

1 f =

LU3: Structure of atoms

• Bohr’s electron shell

LU3: Structure of atoms

• Rydberg equations

• = wavelength (nm)

• RH = Rydberg's constant

= 1.09678 x 10-2 nm-1

• n1 = the lower energy level

• n2 = the higher energy level

LU3: Structure of atoms

• Quantum numbers which describe the distribution of electrons in an atom.

• Each sublevel (orbital) has a letter designation:

• l = 0 is an s sublevel (s = sharp), l = 1 is an p sublevel (p = principal), l= 2 is an d sublevel (d = diffuse), l = 3 is an f sublevel (f =fundamental)

Quantum no. Symbol Defines

Principal n Size/Energy of the orbital

Angular l Shape of the orbital

Magnetic m Spatial orientation of the orbital

Spin s Spin of the electron

LU3: Structure of atoms

• Filling the orbitals

• Aufbau Principle

• Pauli Exclusion Principle

• Hund’s Rule

LU3: Structure of atoms

• Writing down electronic configuration (atom, ion)

• Writing down condensed electronic configuration

• Determination of valence shell and valence electron

– Period and group

• The blocks of periodic table

LU3: Structure of atoms

• Trends in the periodic table Electronic Configuration

Atomic Radii

Ionisation Energy

Electronegativity

Melting Points & Boiling Points

Electrical Conductivity

LU3: Structure of atoms

• Across the period

– Proton ↑, NC ↑, shells the same, SE constant

– Atomic radius ↓, IE ↑, E-ve ↑,

LU3: Structure of atoms

• Down the group

– Proton ↑, NC ↑, shells ↑, SE ↑

– Atomic radius ↑, IE ↓, E-ve ↓

Tips

• Try buat soalan tutorial and examples dlm lecture

• Instead of menghafal semua better lg faham the concept

• Unit is important!!

• Baca soalan, dissect it

• Faham the periodic table

• Formula better hafal

Time management

• 20 MCQ and 6 structure questions

• 2 jam 30 minit (2.00 pm – 4.30 pm)

150 minit

20 MCQ 2 minit per MCQ 40 minit

6 structure questions 15 minit per question 90 minit

Re-check, improve 20 minit

All the best!!

Good Luck