acids and redox 0.0 / 5 ? ChemistryRedoxASOCR Created by: Alx_LghtftCreated on: 10-06-19 15:07 acids All acids contain hydrogen When dissolved in water an acid releases H+ ions into the solution 1 of 14 strong and weak acids strong acids completely disassociate (release all their hydrogens) into an aqueous solution Weak acids only partially dissociate (release a few hydrogens) in aqueous solution most organic acids are weak acids like ethanolic acid 2 of 14 bases and alkalis metal oxides, metal hydroxides, metal carbonates and ammonia are bases a base neutralises an acid to form a salt an alkali is a base that dissolves in water releasing hydroxide ions into the solution 3 of 14 neutralisation of acids with metal oxides and hydr acid is neutralised by a metal oxide or metal hydroxide to form a salt and water only acid + alkali -> salt + water 4 of 14 neutralisation of acids with carbonates carbonates neutralise acids to form a salt, water and carbon dioxide gas 5 of 14 titration titration is used to accurately measure the volume of one solution that reacts exactly with another solution titrations can find the concentration of a solution to identify unknown chemicals find the purity of a substance checking purity is an important aspect of quality control especially for compounds manufactures for human use like medicines, food, and cosmetics 6 of 14 preparing a standard solution a volumetric flask is used to make a solution very accurately volumetric flasks are manufactured to certain tolerances The 100cm^3 flask has a tolerance of + or - 0.2^3 the 250cm^3 flask has a tolerance of + or - 0.3cm^3 7 of 14 the mean titre only use the most accurate titres repeat titrations until two agree within 0.1cm^3 8 of 14 titration calculations work out the amount in moles of the solute in the solution for which you know both the concentration and the volume use stoichiometry to work out the amount in moles of the solute in other solutions work out the unknown information about the solute in the other solution 9 of 14 oxidation number can be thought of as the number of electrons involved in bonding to a different element 10 of 14 rules from elements the oxidation number is always zero for elements in a pure element, any bonding is to atoms of the same elements 11 of 14 rules for compounds and ions each atom in a compound has an oxidation number a sign is placed before the number O = -2 H = +1 F = -1 Na+ K+ = +1 Mg2+ Ca2+ = +2 Cl- Br- = -1 H in metal hydroxides = -1 O in peroxides = -1 O bonded to F = +2 12 of 14 working out oxidation numbers the sum of oxidation numbers = total charge 13 of 14 redox reactions - reduction and oxidation oxidation is the addition of oxygens, the loss of electrons and an increase in oxidation number the reduction is the removal of oxygen, the gain of electrons and decrease in oxidation number redox reactions involve reduction and oxidation if one process happens, so must the other 14 of 14
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