Presentation on theme: "Making Salts Soluble salt Insoluble salt Acid + excess insoluble solid"— Presentation transcript:
1 Making Salts Soluble salt Insoluble salt Acid + excess insoluble solid Acid + alkalititrationAcid + reactive metalSoluble saltAcid + baseAcid + carbonateInsoluble saltDirect combinationPrecipitation
2 Reactions of acidsNeutralisation of:hydrochloric acid gives a chloridesulphuric acid gives a sulphatenitric acid gives a nitrateAcid + metal salt + hydrogenAcid + base* salt + waterAcid + carbonate salt + water + carbon dioxide*Base: A metal oxide or metal hydroxide.An alkali is a water-soluble base.
3 SaltsA salt is an ionic compound which is neither an acid (containing H+) or a base (containing O2- or OH-). A salt is formed whenever an acid is neutralised.Acids, containing H+SaltsIonic compoundsBases, containing OH- or O2-
4 Uses of Salts Plant fertilisers (NPK) Food flavour and preservation (NH4)2SO4, NH4NO3, KH2PO4, …….Food flavour and preservationNaCl, KCl, KNO3…….In toothpasteNaFPhotographic filmAgCl, AgBr
5 Salts are important also in: Proteins and enzymesThe molecules that carry out the chemical reactions of lifeDNA and RNAthe molecules of inheritanceTransmission of electrical impulses along nerves
6 Acid Neutralisation reactions Neutralisation of:hydrochloric acid gives a chloride (containing Cl-)sulphuric acid gives a sulphate (containing SO42-)nitric acid gives a nitrate (containing NO3-)Acid + metal salt + hydrogenAcid + base salt + waterAcid + carbonate salt + water + carbon dioxide
7 Methods of salt making (1) Acid + alkali salt + waterHCl (aq) + NaOH (aq) NaCl (aq) + H2O (l)Titration of acid against alkali for soluble salts of group 1 metals and ammonium5 cm3 sodium hydroxide solution was measured using a pipette and transferred to the conical flask. 2 drops of methyl orange indicator were added. Hydrochloric acid was poured into the burette and the starting reading was recorded. The acid was added to the sodium hydroxide, drop by drop, until the indicator turned from yellow to orange (or red). Charcoal was added to the mixture to absorb the indicator and was removed by filtration. Water was evaporated from the filtrate, leaving sodium chloride crystals.
8 Methods of salt making (2) Acid + excess insoluble solidFor all other soluble saltsSolid is either a moderately reactive metal, a base or a carbonateExcess solid to react with all the acidRemoved by filtration
9 Methods of salt making (3) Precipitation reactionsTo make insoluble salts2 solutions each containing one of the ions in the salt are mixed.Salt is precipitatedSalt is filtered, residue is washed on filter paper and dried.
10 Methods of salt making (4) Direct combination of the elementssodium (l) + chlorine (g) sodium chloride (s)2 Na (l) Cl2 (g) 2 NaCl (s)aluminium (s) + bromine (l) aluminium bromide (s)2 Al (s) Br2 (l) 2 Al Br3 (s)
11 Methods of salt making (1) barium hydroxide (aq) + nitric acid (aq)Ba(OH)2 (aq) HNO3 (aq)2barium nitrate (aq) + water (l)Ba(NO3)2 (aq) H2O (l)2
12 Methods of salt making (1) (b)ammonium carbonate (aq) + sulphuric acid (aq)(NH4)2CO3 (aq) H2SO4 (aq)ammonium sulphate (aq) + water (l) + carbon dioxide (g)(NH4)2SO4 (aq) H2O (l) + CO2 (g)
13 Methods of salt making (1) (c)ammonium hydroxide (aq) + nitric acid (aq)NH4OH (aq) HNO3 (aq)ammonium nitrate (aq) + water (l)NH4NO3 (aq) H2O (l)
14 Methods of salt making (1) potassium hydroxide (aq) + nitric acid (aq)KOH (aq) HNO3 (aq)potassium nitrate (aq) water (l)KNO3 (aq) H2O (l)
15 Methods of salt making (2) Acid + insoluble base salt + waterH2SO4 (aq) + CuO (s) CuSO4 (aq) + H2O (l)
16 Methods of salt making (2) calcium (s) nitric acid (aq)Ca (s) HNO3 (aq)2calcium chloride(aq) hydrogen (g)Ca(NO3)2 (aq) H2 (g)
17 Methods of salt making (2) iron (s) sulphuric acid (aq)Fe (s) H2SO4 (aq)iron (II) sulphate (aq) hydrogen (g)FeSO4 (aq) H2 (g)
18 Methods of salt making (2) calcium carbonate (s) + nitric acid (aq)CaCO3 (s) HNO3 (aq)2calcium nitrate (aq) + water (l) + carbon dioxide (g)Ca(NO3)2 (aq) H2O (l) + CO2 (g)
20 Metal Reactivity Series PotassiumSodiumLithiumCalciumMagnesiumZincIronLeadHydrogenCopperSilverGoldPlatinumReact with cold waterReact with dilute acids and steamReactivityDo not react with dilute acids and steam