Definitions Chapter 1

Mole is the amount of a substance wich contains the same number of chemical species as there are atoms in exactly 12g of the isotope carbon-12

Chapter 1 If the substance is an element; count atoms,

If the substance is a compound, count molecules or ions

the symbol for mole is mol

all matter consists of paricles (atoms or molecules) in motion

as the temperature increases the movement of the particles increases

solid - gas sublimation; gas - solid reverse sublimationsolid - liquid melting; liquid - solid freezing

liquid - gas boiling/evaporating, gas - liquid condensing

atoms can not be created or destroyed during a chemical reaction, they are simply rearranged.

chemical equations monitor these changes as reactants are transformed into products.

the number od atoms of each element must be the same on both sides of the equations

Avogadro's number (L) is the number of atoms in one mole of an element and the number of molecules in one mole of a covalent compound

the molecular formula, which is a multiple of the empirical formula, can only be determined once the relative molecular mass is known

the relative molecular mass can be measured by: 1. a mass spectrometer, or 2. calculated from the ideal gas equation

The molecular formula of some compounds: hydrogen: H2; oxygen: O2; nitrogen: N2; water: H2O; carbon dioxid: CO2; ammoina: NH3; methane: CH4; glucose: C6H12O6

Solid, Liquid, Gas; the three states can be characterized in the terms of the arangement and movement of particles and the force between them

Solid: the particles are closely packed in fixed positions. The interparticle forces restrict the movemetn to vibration about a fixed position. Solids have a fixed shape

Liquid: the particles are still relatively close together. The interparticle forces are sufficiently weak to allow the particles to change places with each other, but their movement is constrained to a fixed volume. Liquid can change shape but not volume.

Gas: the interparticle forces beween the particles are negligible; they are zero for an ideal gas. The particles move freely occupying all the space available to them. Gases have no fixed shape or volume.

when the temperature increases enough for the particles to have sufficient energy to over come the interparticle force a change of state occurs

a balanced chemical reaction is a quantitative description of a chemical reaction can be used to make numerical predictions

all gases have the same molar volume at the same temperature and pressure 1 dm = 10 cm so 1 dm^3 = 10^3 cm^3 298 K and 101.3 kPa (1 atm) is called RTP

one mole of gas occupies 22400 cm^3 under STP = 273 K (0 degrees celsius) and 101.3 kPa (1 atm)

one mole of gas occupies 24000 cm^3 under RTP = 298 K and 101.3 kPa (1 atm)

an increase in volume reduces the frequency of the collision with the walls and so the presure decreases

if the temperature and the amount of gas is kept constant, the pressure HALVES if the volume DOUBLED

ideal gas equation: PV / nT = R; PV = nRT; PV = (m/M)RT when m is in g molar mass (M) = mRT / PV

the experimental yield is generally less than the theoretical yield predicted from the equation. Several reasons for this: - the reaction is incomplete, - there are side reachtions in which unwanted substance are produced, - complete separation of the product from reactions mixture is impossible, - product is lost during transfers of chemicals during ther preparation

P = k1 / V, where k1 is a constant

PV = k1

an increase in temperature increases the average kinetic energy of the particles. The particles move faster and collide with the walls with more energy and more frequency. Which lead to an increase in pressure.

ideal gas equation: PV / nT = R; where R is the gas constant (=8.31 JK-1mol-1)

Chapter 1 Facts 1 a chemical species may be an atom, a molecule or an ion2

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4 the molar mass of an element which exists as atoms is the relative atomic mass expressed in g

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7 Number of moles (n) = mass (m) / molar mass (M); n = m / M8

9 number of particles (N) = number of moles (n) * Avogadro's constant (L); N = nL10

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12

13 the coefficient in an equaton give the molar ratios of the reactant and products

14 mass m = number of moles n * molar mass M; m = nM

15 the theoretical tield is the mass or amount of product produced according to the chemical equation

16 the limiting reactant is the reactant that determines the theoretical yield of product 17 percentage yield = (experimental yield / theoretical yield) * 10018

19 STP = 273 K (0 degrees celsius) and 101.3 kPa (1 atm) 20

21 P1V1 / T1 = P2V2 / T2; the temperature must be in Kelvin 22 density p = mass (m) / volume (v)

a mole is the amount of a substance wich contains the same number of chemical species as there are atoms in exactly 12g of the isotope carbon-12

the mass of one mole of a species is call the malar mass. It is the relative mass expressed in g and units of g/mol or g mol-1

the relative molicular mass (Mr) is definded as the sum of the relative atomic mass of the atoms in the molecule formula. The molar mass (M) of a compound is the relative molecular mass expresed in g

the relative formula mass of an ionic compound is the sum of the relative atomic masses of the atoms in the formula. The molar mass of an ionic compound is relative atomic mass expressed in g

Avogadro's constant (L) has the value 6.02*10^23 mol-1. it has units as it is the number of particles per mole.

the empirical formula gives the ratio of the atoms of different elements in a compound. It is the molecular formula expessed as its simplest ratio

the kelvin is the SI unit of temperature. Temperature in kelvin = temperature in Celsius + 273. the temperature difference measured on either the celsius or Kelvin scale are the same. The absolute temperature of a substance is proportonal to the average kinetic energy of its particles. Absolute zero = 0 K. this is the temperature of minimum kintetic energy.

the kinetic energy of a particle depends on its mass (m) and speed (v). All gases have the same kineticc energy at the same temperature, so particles with dmsllrt msdd move at faster speeds. Kinetic energy = 1/2 mv^2

avogadro's hypothesis states that equal olumes of different gases contain equal numbers of particles at the same temperature and pressure

for a gas: number of moles (n) = volume (v) / molar volume (Vmolar). The molar gas volume at STP is 22.4 dm^3. the molar gas volume at RTP is 24 dm^3

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23 number of moles (n) = (concentration * volume (V)) / 1000

concertration = number of moles (n) / volume of solution (V); the volume is in dm^3. squared brackets are used to repesent concertration.

Chapter 2

all matter is composed of tiny indestructible particles called atoms atoms can not be destroyed or created atoms of the same element are alike in every way

atoms of different elements are different

atoms can combine together in small number to form molecules the atoms of the different elements combine to form covelent molecules of a compound

particle; relative mass; relative charge. Proton; 1; +. Electron; 0.0005; -. Neutron; 1; 0.

number of protons = number of electrons = Z number of neutrons = A - number of protons = A - Z

the loss or gain of electrons makes a very big differnce to the chemical properties

isotopes have the same chemical properties

radioactive isotopes can kill or save humans carbon-14 dating is used to deduce when a body died or to deduce the death of living organism.

mass spectrometer principles vaporization: analizes the element

the smallest unit of an element is an atom

atoms are made up of sub-atomic particles such as protons, electrons, and neutrons. These particles are discribed by their relative masses and charges

atoms have no overall charge, the positive charge of the protons are balanced by the negative charge of the electron. SO the number of protons (atomic number) equal to the number of electrons

the mass of an atom depends on the number of protons and neutrons. (mass of electron is ignored because it is really smallA

ZX; where A is the mass number; Z is the atomic number; X is the element

the number of protons and neutrons never change during a chemical reaction. Electrons are responsible for the chemical change

to be an isotope the mass number has to be different meaning that the number of neutrons is different while the number of protons are the same

radioactive isotopes can be used for: generate enregy in nuclear power stations, sterilize surgical instruments in hosipitals; preserve food; fight crime, detect cracks in structural materials.

cobalt-60 used in radiotherapy: it is the treatment of cancer and other diseases wih ioizing radiation. The treatment damages the genetic material inside cell by knocking off electons and making it impossible for cancerous cells to grow. Normal cells can recover if the treatment is carefully controlled

iodine-131 as medical tracer: can be used as medical tracers because it can monitored by detecting radiation levels. Can be used in form of the compound sodium iodide to investigate the activity of the thyroid glands and diagnose and treat thyroid cancer. another isotope iodine-125 can be used in the treatment of prostrate cancer. they are dangerous if unstable isotopes are used. living organisims can be affcted if exposed to uncontrolled radiation.

ionization: electrons are knocked out due to the high energy electrons producing positively charged ionsacceleration: positve ions are attracted to the negatively charged plates; accerated by the electric field

detection: positive ions of the particular charge/mass ratio are detected and then recorded

red is the least energized, and voilet is the highest line spectrum is some colors of the continuous spectrum missing if high pressure is applied to the gas then emission line sprectrum is produced

electromagnetic radiation is formed by the energy the electron gives out as it goes back to the lower levels.

photons (energy quantum) is released for each electron transition.

infrared radiation is formed when an electron falls to the third or higher energy level. electrons jumping up = atoms absorb energy; electrons moving down = atoms emits energy

deflection: accelerated positive ions are defelcted by a magnetic field. The deflection depends on charge/mass ratio. Ions ith smaller mass are deflected more as they interact more with the magnetic fields

a continuous spectrum is produced when white light is passed through a prism, and all the 7 colors merge smothly into one another

line spectrum can be used as a bar code to identify unknown element, as different elements have different line spectra. It also give us information about the arrangement of the electrons in an atom

when an atom absorbs energy, the electrons move into an orbit ot higer energy levels further from the necleus. Creating an exciting state, however unstable and the electron falls back to the lowest level (aka ground state).

hydrogen produces visible light when the electro falls to the second energy level. If the electron transitions to the first energy level then it is in the UV region due to the higher energy change.

Chapter 2 facts 1 an element is a substance that cnnot be broken down into simpler substances by a chemical reaction

2 a compound is a substance made by chemically comnining two or more elements 3 the atomic number is definded as the number of protons in the nucleus of an atom 4 the mass number is definded as the number of protons plus the number of neutrons 5

6 isotopes are atoms of the same element with different mass number 7 the amount of deflectio of an ion in a mass spectrometer is proportional to the charge/mass ratio 8

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when an atom loses electrons, a positive ion is formed and when it gains electrons a negative ion is formed. Positive ions are called cations and negative ions are called anions

the relative atomic mass of an element (Ar) is the average mass of an atom of the element taking into account all its isotopes and their relative abundance, compared to one atom of carbon-12

the distance between two successive crests (or throughs); curves; is called the wavelength. The frequency of the waves which pass a point in one second. The wavelength and frequency are related by the equation c = f l where c is the speed of light, l wavelength.

the energy of a photon of electromegnatic radiation is directly proportional to its frequency and inversely proportional to its wavelength . It can be calculated from Planck's equation E=hf given in the B data booklet

the ionization energy is the minimum energy needed to remove an electron from the ground state of a gaseous atom ion or molecule.

Chapter 3

the elements are placed in an increasing atomic number.

the gap between groups 2 and 3 are filled with transition elements

atomic radii increase down the group and decreases across the period

the ionic radii increases down a group as the number of electron shell increases.

the most electronegative element is fluorine and the least electronegative element is francium

shielding is when there are other electron levels between the outter shell and the neucleus not allowing the outershell to full be attacted by the nucleus

the effective nuclear charge increases across (left to right) the period as there is no change in the number of inner electrons.

the effective nuclear charge increases down the group as there is a huge difference in the number of inner electrons.

the atomic radii increases down the group as the number of occupied electron shells given by the period number increases

the atomic radii decreases across the period as the attraction between the nucleus and the outter shell electrons increases as nuclear charge increases.

ionic radi across period: positve ions are smaller then their parent atoms as the atom losses the outer shell. Negative ions are larger than their parent atoms as the addition of electrons into the outer shell, the increased electron replusion between the electrons in the outter shell cause the electrons to move further apart.

ionic radii: decreaes from groups 1 to 4 for the positive ions. Because of the increase in nuclear charge and the increased attraction between the nucleus and the electoons in the outter shell. Decreases for from group 4 to 7 for the negative ions. because of the increase in the nuclear charge

period 3 ionic radii: the posive ions are smaller than the negative ions because the positive ions have only 2 occupied electron shells and the negative ions have 3 occupied electron shells.

ionization energy increases across a period because of the increase in nucleur charge causing an increase in the attraction between the outer electrons and the nucleus, making it harder to remove the electrons

ionization energy decreases down the group as the electrons that are being removed are further away from the nucleus and also because of the shielding, which weakens the nuclear charge.

an element with a high electronegativity has strong electron pulling power and an element with a low electronegativity has weak pulling power.

electronegativity increases across a period because of the increase in nucleur charge causing an increase in the attraction between the outer electrons and the nucleus, making it harder to remove the electrons

electronegativity decreases down the group as the electrons that are being removed are further away from the nucleus and also because of the shielding, which weakens the nuclear charge.

melting point decreases down group 1: the element have matellic structures which are held together by attractive forces between delocalized outer electrons and the positively charged ion

melting point increases down group 7: the elements have molecular structures which are held toegther by van der Waals intermolecular forces. These incease with the number of electrons in the molecule

period 3 elements are solid at room temperature except chlorine and argon. element in the same group have similar chemical properties Noble gases are : colorless, they are monatomic; exist as single atoms, they ar very unreactive noble gases have the highest ionization energies they have a stable octet; they have a complete outer shell group 1 the alkali metals, are too reactive

group 1 has the lowest ionization energy and lowers down the group group 1 reaction with water: produces hydrogen and the metal hydroxide.

reactions get more vigorous when going down the group look at page 59 to write the equation for the reation:

the reactivity decreases down the group group 7 reaction with group 1 metals form ionic halidesthe most vigorous reaction takes place between 2 elements that are the furthest from each other.

basic oxides: the basic oxide ion combined with two H+ ions form water look at page 62 to write the equation for the reaction

group 1 oxides dissolve in water to form alkaline solutions and form hydroxide ions look at page 63 to write the equation of the reaction

acidic oxides: non metallic oxides when reacted wth water form acidic solutions

the melting point generally increases across a peroid and reaches maximum at group 4. then fully reach a minimum at group 0. in period 3 the bonds are covelent and weak van der Waals attraction between simple molecules and single atoms

first 3 elements properties of group 1: physical: they are good conductors of electricity, they havelow densities, they have grey surfaes when freshly with a knife. Chemical: they are very reactive metals, and they form ionic compounds with non-metals

when the first 3 elements of group one are dropped in to distilled water the following is observed: lithium floats and reacts slowly, keeping its shape. Sodium reacts so vigorously that the heat is sufficient to melt the unreated metal, which forms a small ball that moves around on the water surface. Potassium reacts even more vigorously to product sufficient heat to ignite the hydrogen produced. it produces lilac coloed flame and moces excitedly on water surface

properties of group 7: the halogens. Physical propertie: they are colored, they show a gradual change from gases (F2 and Cl2) to liquid (Br2) to solid (I2 and At2). Chemical: they are very reactive. They form ionic compounds with metals or covent compounds with other non-metals

bondin of period 3 oides:oxides of elements Na to Al have giant ionic structures, oxides of phosphorus, sulfur and chlorine are molecules covalent, oxides of silicon has a gaint covelent structure

Acid base character of the period 3 oixide: ionic oxides are basic, non metal ions;covelent are acidic, and aluminium oxide and silicon oxide are amphoteric; reacts with both acids and bases

look at page 63 to write the equation of the reaction

Chapter 3 Facts1

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3 electronegativity is the ability to attract electrons in a covelent bond

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5 the more reactive halogen displaces the ions of the less reactive halogen

6 amphoteric oxides show both acidic and basic properties. 7 alkalis are bases which are soluble in water. They form hydroxide ions in aqueous soslutions

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the colums in the periodic table are called groups. The groups number gives the number of electrons in the outer shell. The rows in the periodic table are called peroids. The period number gives the number of occupied electron shells

the first ionization energy of an element is the nergy required to remove one mole of elctrons from one more of gaseous atoms

chemical properties of an element are largely determined by the number of electrons in the outer shell

oxides of metals are ionic and basic. Oxides of the non-metals are covelent and acidic. Ocides of some elements in the middle of the periodic table are amphoteric.

Chapter 4

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Chapter 4

groups 1-3 lose electrons

groups 5-7 gain electrons

polyatomic ions are ions that are made up of more than one atom which together losses or gains electrons

ionizatio is when electrons are transferred between atoms, can only happen between metals and non metals

compound ending in -ate refers to ions that contain oxygen bonded to another element

after ionizations the name of the non metals changes, the eneding of the name changes to -ide

ionic chatachter of compounds can be predicted from two factors:

2. electronegativity

a doubledond is formed when two electron pairs are shared a triple bond is formed when three elctron pairs are shared look at page 74 to see the steps of how to do the lewis structure look at page 75 to see the steps of how to the lewis structure for ions bond is non polar covalent if the difference of the electronegativity is has no difference 0.0-0.4bond is polar covalent if the difference of the electronegativity is up to >1.8 (0.5-2.0)bond is ionic if the difference of the electronegativity is < 1.8 (> 2.0)

refer to ibscrewed notes for the shape and angle of the bond

allotropes are different forms of an element in the same physical state carbon has three allotropes: graphite, diamond, fullerene C60 (look at 81 for more details)

substances that have a van der waals intermolecule force have low melting and boiling point

the strength of the dipole-dipole intermolecule force depends on the degree of polarity within the bond

dipole dipole are stonger then van der waals

hydrogen bonds are the stongest of all 3 inter moleculat fources

ionic bond is when the oppositely charged ions are attracted to each other and are held together by electrostatic forces

1. position of the elemenet in the periodic table: highesy tendency to form compound ions will be between elements on the bottom left and those on the top right of the periodic tabke

van der waals force is the weakest intermolecule force. Their strength increases as the number of elctrons within a molecule increases. And that is when the Mr increases.

when one end of the molecule has a partial positive charge while the other end has a partial negative charge then it is known as permanent dipole, hence AKA dipole-dipole attraction

hydrogen bonding is present when a molecule contains hydrongen covalently bonded to fluorine, nitrogen or oxygen

delocalized is when the outer electron tends to wander of when there is no other elemet present to accept the electron and form an ionic compound

malleable: that the metal can be shaped under pressure ductile: that they can be drawn out in to threads FOR THE PYSICAL PROPERTIES REFER TO IBSCREWED NOTES

metal are good electricity conductors because of the delocalized electrons as they can move freely which then responses as the voltage

Chpater 4 facts

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5 length of bonds: single bond > double bonds > triple bonds

6 strenth of bonds: sngle bond < double bond < triple bond

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book reference pages 67

* 69 polyatomic ions * 74

77* 81

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an ion is a charged particle. Ions form from atoms or from groups of atoms by transfer of one or more electron

when an atom loses electtons it froms a positive ion AKA cation. When an atoms gains electrons it forms a negative ion AKA anion. The nuber charges on the ion formed is equal to the ion formed is equal to the number of electrons transferred

a covelent bond is the electostatic attraction between a pair of electrons and positvely chareged nuclei. A molecule is a group of atoms held together by covelent bonds

molecules containing two atoms are described as diatomic, those containing three atoms are triatomic

the nature of a bond between two atoms, that is, whether it is covalent, polar or ionic can be predicted from the position of the element in the periodic table or from their electronegativity value. The firther apart on the periodic table they are the more ionic; the closer the more covalent.

non bonded pairs of electrons on the central atom play a crucial role in determining the distribution of the electron pair, but the overall shape of the molecule depends only on the positionns of the bonded atoms

if you compare two covelent substances of similar molecular mass, the more polar substance will have a higher boiling point

hydrogen bonding oly occus between mlecules which contain hydrogen bonded directly to fluorine, nitrogen or oxygen

Chapter 5

Chapter 5

Chapter 5 facts 1 the joule is the unit of energy and work. 2

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4 for exothermic reactions 56789

10111213141516171819202122

an open system can exchange energy and matter with the surroundings. A closed system can exchange energy but no matter with the surroundings

it is important to give the state symbols in thermochecmical equations as the energry changes depend on the state of the reactants and the products