IB Chemistry revision notes and syllabus Aura Virtual Campus such a table is known as the electrochemical series, and that the standard hydrogen half-cell (not the copper half-cell) is used as the reference half-cell. Practical work with voltaic cells Voltaic cells offer much scope for laboratory investigations, because they use relatively simple materials. For example, as a design experiment that will count as part of your internally assessed coursework, your teacher may simply say to you, "Investigate an aspect of voltaic cells." From now on you are on your own, and a good investigation should mean that each person in the class can come up with a different problem to investigate. To focus on a particular research question you need to be able to identify which variables you can manipulate and which you can keep constant. Once you have identified your own problem or research question to investigate, you need to plan how to carry this out experimentally. 3 Does brass, when used in electrochemical cells, tend to behave as copper or as zinc?
IB Chemistry standard level: Organic chemistry - other functional groups 10.3.1: Describe, using equations, the reactions of alkenes with hydrogen and halogens. Alkenes have a double bond which acts as a focus for attack by species that are attracted by electrons (electrophiles). This allows alkenes to react with both hydrogen and halogens. Reaction with hydrogen Hydrogen gas will react with alkenes in the presence of a nickel catalyst at 150ºC. This reaction is used in industry to convert vegetable oils into margarine. This increases the melting point of the vegetable oil until it becomes a waxy solid (margarine). Reaction with halogens Halogens react with alkenes at room temperature. C2H4 + Cl2 C2H4Cl2 This reaction is utilised to test for the presence of double bonds (unsaturation). C2H4 + Br2 C2H4Br2 Iodine does react with double bonds, but only slowly and with difficulty. 10.3.2: Describe, using equations, the reactions of symmetrical alkenes with hydrogen halides and water Reaction with hydrogen halides Hydrogen halides react with alkenes at room temperature. nC2H4
IB Chemistry Revision Notes - Chemistry IB Chemistry/Environmental Chemistry E1 Air Pollution[edit] E.1.2 Evaluate the current methods for the reduction of air pollution.[edit] E2 Acid Deposition[edit] E.2.1 State what is meant by the term acid deposition and outline its origins.[edit] Acid deposition is the process by which acidic particles, gases, and precipitation leave the atmosphere. E.2.2 Discuss the environmental effects of acid deposition and possible methods to counteract them. Some effects of acid deposition include: Leeches important nutrients from soil such as Ca2+, Mg2+, and K+ which can lead to reduction in chlorophyll and therefore the ability to photosynthesize.Can kill aquatic life in lakes and rivers, and nitrates can lead to eutrophication.Erosion of stone which contains calcium carbonate (such as marble)Irritation of the mucus membranes increases the risk of respiratory illness such as asthma, bronchitis and emphysema Acid deposition can be counteracted by lowering the amount of sulfur and nitrogen oxides with: E3 Greenhouse Effect[edit] Formation:
§7 Equilibrium - IB Chemistry SL Recall the thermal decomposition of calium carbonate (found in the natural world as limestone) ... where the forward reaction and the backwartd reaction are represented as one. Of course, if the products are constantly forming from reactants BUT, at the same time, reactants are constantly forming from products where does it all stop.The short answer is ... it doesn't. The classic equilibrium reaction you should be aware of is the catalytic production of ammonia gas by the Haber process. N2O4 ⇌ 2NO27.2 The Position of Equilibrium: 7.2.1 To help understand this chemists have developed a measure from the final concentrations of the species in an equilibrium mixture for a reaction equation ... aA + bB ⇌ cC + dDnote : that if the reaction proceed so that a great deal of product forms at the expense of rectant Kc>>1while Kc<<1 if the reaction hardly proceed s at all, that is there are very little products formed. 7.2.3 Le Chatelier's Principle
IB Chemistry Review: Option E: Environmental Chemistry (SL) E1 Air Pollution E.1.1 Describe the main sources of carbon monoxide (CO), oxides of nitrogen and sulfur, particulates and volatile organic compounds in the atmosphere. E.1.2 Evaluate the current methods for the reduction of air pollution. E2 Acid Deposition E.2.1 State what is meant by the term acid deposition and outline its origins. Acid deposition is the process by which acidic particles, gases and precipitation leave the atmosphere. Pure rainwater usually contains dissolved carbon dioxide, so is acidic with a pH of 5.6. Reactions we need to know: Burning of sulfur and nitrogen: Oxides of sulfur and nitrogen with water: We need to know the origins of acid deposition. E.2.2 Discuss the environmental effects of acid deposition and possible methods to counteract them. Environmental effects: Acid rains leach Mg2+ from the soil, which reduces chlorophyll levels. Possible methods to counteract acid rain: E3 Greenhouse effect E.3.1 Describe the greenhouse effect. Greenhouse gases (esp.