ib chemistry

Slide 1:IB CHEM Notes Daniel Paley

Slide 2:Energetics Unit 5

Slide 3:5.1 Exothermic and Endothermic Reactions

Slide 4:5.1.1 Exothermic reaction: Causes the temperature of the surroundings to increase. Endothermic reaction: Causes the temperature of the surroundings to Decrease. Enthalpy Change of reaction: ?H°: The difference between enthalpy of the products and enthalpy of reactants under standard conditions

Slide 5:5.1.2 Combustion and Neutralization are Exothermic processes.

Slide 6:5.1.3 Exothermic ? ?H<0 Endothermic ??H>0 If change in H is negative the reaction is Exothermic If change in H is Positive the reaction is Endothermic

Slide 7:5.1.4

Slide 8:5.1.4 Changing an element to a positive ion the enthalpy change is positive. For change of state s ? l ? g change in enthalpy is positive. For change of state g ? l ? s change in enthalpy is negative. Bond breaking is Endothermic Bond making is Exothermic

Slide 9:5.2 Calculation of Enthalpy Changes

Slide 10:5.2.1 Specific Heat capacity: the amount of heat energy required to raise the temperature of 1.00 g of the substance by 1.00°C or 1.00 K ??=??×??×??? q=heat energy change in J m=mass of the substance in g c=specific heat capacity in J ? -1 g -1 ?T=change in temperature in ?

Slide 11:5.2.2 Refer to book page 198 Using a Calorimeter Basically you hold an insulated beaker over a flame or react a substance in an insulated beaker and measure the temperature change

Slide 12:5.2.3 Thermochemical equation: An equation that gives the relevant ?H value for that particular equation exactly as it is written

Slide 13:5.2.4 Heat of Combustion: The amount of heat produced by combustion of one mole of the fuel. Refer to page 198 in book

Slide 14:5.3 Hess’s Law

Slide 15:5.3.1

Slide 16:5.4 Bond Enthalpies

Slide 17:5.4.1 Average Bond enthalpy: The amount of energy required to break one mole of bonds in the gaseous state averaged across a range of compounds containing that bond.

Slide 18:5.4.2 Bond Breaking is endothermic. Bond Making is exothermic Enthalpy of reaction = S???? ???? ?? ?????????? ???????????? -?????? ??????(?????????? ????????????) Where D = the bond enthalpy per mol of bonds

Slide 19:Oxidation And Reduction Unit 9

Slide 20:9.1 Oxidation and Reduction

Slide 21:9.1.1 Oxidation is loss of electrons and a gain in oxidation number. Reduction is gain in electrons and loss in oxidation number OIL RIG (Oxidation is loss, Reduction is gain)

Slide 22:9.1.2 The oxidation number in each atom in a pure element is 0 The oxidation number in a monatomic ion is equal to the charge of the ion. Oxygen has an oxidation number of -2 (Except ?? ?? 2 [+2] and peroxides [-1]) Hydrogen has an oxidation number of +1 (Except in metal hydrides [-1]) For a molecule the sum of the oxidation numbers equals 0 For a polyatomic ion the sum of the oxidation numbers equals the charge on the ion. In a compound, the most electronegative atom is assigned the negative oxidation number.

Slide 23:9.1.3 Metals have roman numerals for their charge, ie Iron (2+) is Fe(II) and iron (3+) is Fe(III). Other elements can also have a range of oxidation states such as Nitrous Oxide.

Slide 24:9.2 Redox Equations

Slide 25:9.2.1 Half equations indicate which reactant is reduced and which oxidized and by how much, the electrons and Hydrogen atoms are then used to balance the equation (Make charges equal)

Slide 26:9.2.2 Writing and Balancing Redox equations Write the formula of the species being oxidized/reduced and its conjugate pair. Balance the number or atoms of the species being oxidized/reduced. Balance the number of oxygen atoms by adding ?? 2 ?? to the equation. Balance the number of hydrogen atoms by adding ?? + to the equation. Balance charges by adding electrons. Add states for all species.

Slide 27:9.2.3 A redox equation causes another reactant to be reduced. (Is oxidized) An oxidizing agent causes another reactant to be oxidized. (Is reduced)

Slide 28:9.2.4 The reducing agent in a redox equation is the element which reduced the other element (The element that was oxidized or lost electrons) The oxidizing agent in a redox equation is the element which reduced the other element (The element that was reduced or gained electrons)

Slide 29:9.3 Reactivity

Slide 30:9.3.1 Standard electrode potential ?? Ø Is equal to the ?? Ø volts of one element – the ?? Ø volts of another.

Slide 31:9.3.2 (NS) If the ?? Ø are high then the reaction will be spontaneous . If the ?? Ø are low then the reaction will be slow.

Slide 32:9.4 Voltaic cells

Slide 33:9.4.1, 1 Two reactions take place with different elements. Each element is placed in a solution of its own ions + an acid (i.e. nitric acid) The element that oxidizes loses electrons which travel through a wire to the other element which is reduced and so wants to gain electrons (From the element that oxidized) A salt bridge allows the electrons to flow back to the oxidizing reaction so that the oxidizing reaction does not become + charged and the reducing reaction does not become – charged. As electrons flow through the wire it is now a circuit

Slide 34:9.4.1, 2 i.e.

Slide 35:9.4.2 Oxidation occurs at the negative electrode (Anode) and reduction occurs at the positive electrode (Cathode)

Slide 36:9.5 Electrolytic cells (NYD)

Slide 37:9.5.1

Slide 38:9.5.2

Slide 39:9.5.3

Slide 40:9.5.4

Slide 41:Organic Chemistry Unit 10

Slide 42:10.1 Introduction to Organic Chemistry

Slide 43:10.1.1 HOMOLOGOUS SERIES Group of carbon compounds with the same general formula. Differ by CH2 groups Similar chemical properties.

Slide 44:10.1.2

Slide 45:10.1.3 Empirical Formula The lowest whole number ratio of elements in a compound. Molecular Formula Shows the actual numbers of all the atoms in a molecule of the compound. Structural Formula Shows the way in which the molecules are bonded together with each other, useful when visualizing the shape of molecules.

Slide 46:10.1.4 Isomers Compounds with the same molecular formula but with different arrangements of atoms.

Slide 47:10.1 Groups

Slide 48:Alkanes

Slide 49:Alkenes

Slide 50:Alcohols

Slide 51:Halogenoalkanes

Slide 52:Aldehydes

Slide 53:Keytones

Slide 54:Carboxylic acids

Slide 55:Rules of IUPAC names Meth = 1 Carbon Eth = 2 Carbons Prop = 3 Carbons But = 4 Carbons Pent = 5 Carbons Hex = 6 Carbons Hept = 7 Carbons Oct = 8 Carbons Non = 9 Carbons Dec = 10 Carbons

Slide 56:10.1.11 Amino acids have a NH2 off the C atom. Esters have a second oxygen bonded to the carbon atom. (CH3OCH3)

Slide 57:10.2 Reactions of alkanes

Slide 58:Combustion 10.2 Complete combustion of an alkane means an alkane burns in excess oxygen and results in ?? ?? ?? (??) +?? ?? ?? (??) and burns with a clean flame. Incomplete combustion of an alkane means the alkane burns in limited oxygen and results in ?? ?? ?? (??) +?? ?? (??) or if there is even less oxygen ?? ?? ?? (??) + ?? (??)

Slide 59:Uv Light 10.2 Initiation ?? ?? 2 +???? ??????h???????·+????· Propagation ?? ?? 4 +????· ??? ?? 3 ·+?????? ?? ?? 3 · +?? ?? 2 ??? ?? 3 ????+????· Termination ????·+????· ??? ?? 2 ?? ?? 3 ·+????· ??? ?? 3 ???? ?? ?? 3 ·+C ?? 3 · ? ?? 2 ?? 6

Slide 60:10.3 Reactions of alkenes

Slide 61:Addition 10.3 These simply require an alkene and a Halogen, hydrogen halide, hydrogen gas, or water. With a halogen or hydrogen halide, i.e. ?? ?? 2 or ?????? the alkene will simply just react as it is energetically favorable. This forms a Halogenoalkane. With hydrogen the reaction requires a ???? Catalyst for the reaction to take place. This forms an alkane. With water the reaction requires heating and ?? 3 ?? ?? 4 catalyst and this reaction form an alcohol.

Slide 62:Polymerization 10.3 The alkenes double bond breaks to allow it to attach to another alkene and addition polymerization occurs. ???? ?? 2 ?? ?? 2 ? ?? ?? 2 ?? ?? 2 ?? Ethane ? Polyethane

Slide 63:10.4 Reactions of alcohols

Slide 64:Oxidation 10.4 An oxidizing agent (i.e. ?? ?? 2 ?? 7 2- , ?? + ) is added to an alcohol to oxidise it. A primary alcohol is oxidized into an aldehyde or if extra heat is added is oxidized into a carboxylic acid. A secondary alcohol is oxidized into a ketone.

Slide 65:10.5 Reactions of Halogenoalkanes

Slide 66: ?? ?? 1 Reaction 10.5

Slide 67: ?? ?? 2 Reaction 10.5

Slide 68:10.6 Reactions Pathways

Slide 69:Reaction pathways 10.6