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grams Therefore‚ mass of Water that has escaped = (mass of crushed hydrate) - (mass of crushed hydrate after heating) Mass of H2O = 2.98 grams Therefore mols of H2O = (2.98g) * (1mol)\(18g) = .165 mols H2O So‚ mols of Cu2SO4 = (3.49g) * (1mol)\(223.15g) = .015 mols Cu2SO4 Divide by .015 Common ratio: Cu2SO4 = 1 H2O = 10 Therefore‚ empirical formula of Cu2SO4 . H2O should be: Cu2SO4 . 10H2O Conclusion: A hydrate is a substance that holds water in a certain ratio. As Hydrates are compounds

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temperature: Decolourisation of KMnO4 occurs immediately CH2 = CH2 + [O] + H2O → CH2 – CH2 ⏐ ⏐ OH OH (a) Insert a glowing splint into the hydrocarbon hydrocarbons: Burns with smoky flame Aromatic hydrocarbons (b) Add concentrated nitric(v) acid and concentrated sulphuric acid at 55 °C: Yellow oil with bitter almond smell produced benzene NO2 + HNO3 (HONO2) Alkylbenzenes – CH3 CH3 + H2O Add alkaline KMnO4 and boil: Decolourisation of KMnO4; brown precipitate

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Part I: Properties of Hydrates 1.Place about 0.1 g of the following compounds in each one test tube: CuSO45 H2O‚ CoCl26 H2O‚ NiCl26 H2O‚ and KAl(SO4)212 H2O. 2. Heat each test tube gently over a Bunsen burner flame and record your observations in your notebook. 3. After the sample has cooled‚ add a few drops of deionized water. What happens and what can be concluded? Part II:

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COrdination compounds Question 9.1: Explain the bonding in coordination compounds in terms of Werner’s postulates. =Werner’s postulates explain the bonding in coordination compounds as follows: (i) A metal exhibits two types of valencies namely‚ primary and secondary valencies. Primary valencies are satisfied by negative ions while secondary valencies are satisfied by both negative and neutral ions. (In modern terminology‚ the primary valency corresponds to the oxidation number of the metal

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 CO2(g) 3. Metal oxide  +  water  →    metallic hydroxide EX. MgO(s)  +   H2O(l)  →    Mg(OH)2(s) 4. Nonmetallic oxide  +  water  →    acid EX. CO2(g)  +  H2O(l)  →    ; H2CO3(aq) 5. Metal + nonmetal  →    salt EX. 2 Na(s)  +  Cl2(g)  →    2NaCl(s) 6. A few nonmetals combine with each other. EX. 2P(s)  +  3Cl2(g)  →    2PCl3(g) These two reactions must be remembered: 1. N2(g)  +  3H2(g)  →    2NH3(g) 2. 3. NH3(g)  +  H2O(l)  →    NH4OH(aq) Examples of decomposition reactions: 1. Metallic

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Temperature (°C) Convert to: g NH4Cl 100 mL H2O 1 2g 5.0 44°C 40g NH4Cl 2 2.2g 5.0 50°C 44g NH4Cl 3 2.4g 5.0 57°C 48g NH4Cl 4 2.6g 5.0 61°C 52g NH4Cl 5 2.8g 5.0 66°C 56g NH4Cl Data Table 2: Experiment Results Solubility of NH4Cl (g/100 mL H20) Crystallization Temperature (°C) 40g NH4Cl 44°C 44g NH4Cl 50°C 48g NH4Cl 57°C 52g NH4Cl 61°C 56g NH4Cl 66°C Data Table 3: Solubility Results Compound Mixture Soluble or Insoluble? Distilled H2O + Na2SO4 soluble Corn Oil + Na2SO4 insoluble

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(aq) → Cu2+ (aq) + 2NO2(g) + 2H2O(l) Cu(s‚ brown) + 4H3O+ (aq) + 2NO3 – (aq) → [Cu(H2O)6]2+ (aq‚ blue) + 2NO2 (g‚ gas) (b) Part II H3O+ (aq) + OH- (aq) → 2H2O(l) [Cu(H2O)6]2+ (aq‚ blue) + 2 OH- (aq) → Cu(OH)2 (s‚ blue) + 6H2O (l) (c) Part III Cu(OH)2 (s‚ blue) CuO (s‚ black) + H2O (l) (d) Part IV CuO (s‚ black) + 2 H3O+ (aq) + 3 H2O (l) → [Cu(H2O)6]2+ (aq‚ blue) (e) Part V [Cu(H2O)6]2+ (aq‚ blue) + Zn(s‚ gray) → Cu(s‚ brown) + Zn2+ (aq‚ colorless) + 6H2O (l) Zn(s‚ gray)

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Chemical Reaction Aluminum hydroxide Al(OH)3 Al(OH)3(s) + 3 HCl(aq) -----> AlCl3(aq) + 3 H2O(l) Calcium carbonate CaCO3 CaCO3(s) + 2 HCl(aq) -----> CaCl2(aq) + H2O(l) + CO2(g) Magnesium carbonate MgCO3 MgCO3(s) + 2 HCl(aq) -----> MgCl2(aq) + H2O(l) + CO2(g) Magnesium hydroxide Mg(OH)2 Mg(OH)2(s) + 2 HCl(aq) -----> MgCl2(aq) + 2 H2O(l) Sodium bicarbonate NaHCO3 NaHCO3(aq) + HCl(aq) -----> NaCl(aq) + H2O(l) + CO2(g) In this experiment‚ several brands of antacids will be analyzed to determine

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pairs of acid and base. Theory: When alkali neutralizes an acid‚ a salt and water are formed. Aqueous hydrogen ions‚ H+(aq) from the acid react with the hydroxide ions‚ OH-(aq) from the alkali‚ forming water. Ionic equation: H+ (aq)+OH- (aq) → H2O (l) The identity of the salt will depend on the nature of the acid and alkali used. The combination of H+ and OH- ions in this way releases energy. In this practical‚ the enthalpy changes accompanying different neutralization reactions will be measured

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occurs; the zinc appears to “dissolve” and what appears to be “steam” comes off out of container. | single-displacement reaction | Zn + 2 HCl (aq) --> ZnCl2(aq) + H2(g) | 3. Black smoke occurs | decomposition reactions | 2 (H2O2)(aq) MnO2 2 (H2O) + (O2) | 4.  reddish-brown deposit on the surface of iron; surface of the iron is found corroded; the blue solution turns light green | single-displacement reaction | Fe + CuSO4(aq) --> FeSO4 + Cu | 5. PbSO4 (milk white) | double-displacement

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