Industrial_Chemistry

!"# !"# $ $ % Natural resource: & ( ' )* " + , " + / " . Steps to answering this question: 1. Name a limited natural resource (guano) 2. Discuss issues associated with the increased need for the resource 3. Identify replacement materials and/or current research into replacements 4. Use appropriate structure for discussion (opening argument, discussion of issues and concluding remarks) ) 0 ! " 1 # $ % $& % $ % $ Recall: 2 % / 3 5 #$ 1 1 4 Factors which affect the equilibrium in a reversible reaction: % , % 1 • 7 • 7 • 7 1 % $ % ( $ " ! ' " ( " " 1 1 1 1 6 1 1 . ( 2% 3 1 8 1 # aA + bB ↔ cC + dD 7 % , ( 6 " . # [C ]c [ D ]d =K [ A]a [ B]b Interpretation of the equilibrium constant: 1 1 9 1 7 / 1 1 , : , & " 1 5 1 1 . 1 : '( ) & " ( 1 Recognise: 1 1 # 1 " , $ : ; $ : < $ : = 1 > + * + • • • • • & # #' , !0 # . ! ! ! Process of sulfur extraction: . + , + % 5 7 1 . AA BC @* %" ) Property of sulfur which allow its extraction: + . • $ > %" • • + + $ 8 # @* %" / Environmental issues: 7 8 , D . * H 2 SO4 . / . 1 5 5 Steps to producing sulfuric acid: % # & ! $ . # + Conditions necessary: . . S ( s) + O2 ( g ) ↔ SO2 ( g ) + ∆H . . ****% . . !*** % SO2 . # & ! SO3 ! ! + . . . . . " 1 . . V2O5 " . V2O 2 SO2 ( s ) + O2 ( g ) ← 5 → 2 SO3 ( g ) + 197 kJ  Conditions necessary: + $ $ % 9 . /0 # . !**5BB**%" 5) 1 " 1 , . ! . . " 1 $ " . H 2 S 2O7 " > $ 1 . SO3 ( g ) + H 2 SO4 (l ) → H 2 S 2O7 (l ) 1 # & A C H 2 S 2O7 (l ) + H 2O (l ) → 2 H 2 SO4 (l ) SO2 SO3 Conditions necessary for producing SO2 : S ( s ) + O2 ( g ) → SO2 ( g ) + ∆H . . 1 . EE E" ****% !*** % . SO2 SO3 Conditions necessary for producing SO3 : V2O 2 SO2 ( s ) + O2 ( g ) ← 5 → 2 SO3 ( g ) + 197 kJ  + . $ $ % 9 . , 1 . . 1 . . !**5BB**%" . . / 1 , " 5) . 1 1 " , 5) . SO2 SO3 " 0 $ . + . . 1 2 SO2 ( s ) + O2 ( g ) ↔ 2 SO3 ( g ) + 197 kJ $ , . " ! BB**% / # $ !***% " ! 2 % $ . AFC . Sulfuric acid as an oxidizing agent: + . / G # Zn( s ) + 2 H (aq ) → Zn ( aq ) + H 2 ( g ) + " . 2+ ( # Zn( s ) + H 2 SO4 ( aq ) → ZnSO4 (aq ) + H 2 ( g ) ! " . / − . 2− Sn( s ) + 2 H + (aq ) + 2 HSO4 (aq ) → Sn 2+ (aq ) + SO2 ( g ) + 2 H 2 O(l ) + SO4 (aq ) Sulfuric acid as a dehydrating agent: % # $ C 2 H 5OH (l ) + H 2 SO4 (l ) → C 2 H 4 ( g ) + H 2 O(l ) % # C12 H 22 O11 ( s) → 12C ( s ) + 11H 2 O( g ) ! ! Describe the exothermic nature: 7 . H 2 SO4 (l ) + H 2 O (l ) → H 3O (aq ) + HSO4 (aq ) + heat Explain the exothermic nature: " # + 8 + $ -5 # H 2 SO4 (l ) + H 2 O(l ) → H 3 O (aq ) + HSO4 ( aq ) # HSO4 (aq ) + H 2 O(l ) ↔ H 3O (aq ) + SO4 ( aq ) " . " . -H . 3 $ + + − + − − + 2− # " 2 H (aq ) + 2 H 2 O(l ) → 2 H 3O + (aq ) ∆H hydration = −2182kJ .mol −1 Concerns with sulfuric acid: 7 Safety precautions# + I " , ) + . . 8 . , / B Safety precautions# % 1 0 + 4 & & 3 $ • • • % % ( 1 )C " " % . $ + ! ! & . 1 " Electrolysis: The process of driving a non-spontaneous redox reaction to occur by means of electrical energy, to separate ions at molten state. Electrolytic cell: an electric cell in which the process of electrolysis occurs Galvanic and electric cells: & . 9 $ 5 . . & 8 . 8 . * " ! 9 2 # General terms: $ Main features: % . / + " − . / − + Anode reaction: 2Cl (aq ) → Cl2 ( g ) + 2e " . − . − Cathode reaction: 2 H 2 O (l ) + 2e → H 2 ( g ) + 2OH ( aq) # 2Cl (aq ) + 2 H 2 O (l ) → Cl 2 ( g ) + H 2 ( g ) + 2OH (aq ) 7 8 1 # 2 Na ( aq ) + 2Cl ( aq ) + 2 H 2 O (l ) → Cl2 ( g ) + H 2 ( g ) + 2 Na ( aq ) + 2OH ( aq ) # 2 NaCl ( aq) + 2 H 2 O (l )   → 2 NaOH ( aq) + Cl2 ( g ) + H 2 ( g )  electrolysis + − + − − − ! & ! # $ && % $ % $ % @ The Mercury Process . Description of equipments: , 1 . . . Basic chemistry (must memorize equations): $ , - Cathode reaction: 2 Na ( aq ) + 2e + Hg (l ) → 2 Na ( dissoved % Anode reaction: 2Cl (aq ) → Cl2 ( g ) + 2e , − − + − in Hg ) 5 # 2 Na / Hg + 2 H 2O(l ) → 2 NaOH ( aq) + H 2 ( g ) + 2 Hg (l ) # 2 Na + + 2Cl − + 2 H 2 O (l ) → 2 Na + + 2OH − + H 2 ( g ) + Cl2 ( g ) Advantages: • $ • $ • ( Technical difficulties: • . • J • 2 • G 1 1 . . F Environmental difficulties: • , + • . % . # • • $ + . . The Diaphragm Process $ . Description of equipments: , 1 , 5 . . Basic chemistry (must memorize equations): $ . / " " Anode reaction: 2Cl − (aq ) → Cl2 ( g ) + 2e − + " . Cathode reaction: 2 H 2 O (l ) + 2e → H 2 ( g ) + 2OH ( aq) # − − . 2 Na + (aq ) + 2Cl − (aq ) + 2 H 2O(l ) → Cl2 ( g ) + H 2 ( g ) + 2 Na + (aq ) + 2OH − (aq ) . Advantages: • • 1 2 1 G - Technical difficulties: % • 1 • . • , 5" . C " 1 Environmental difficulties: The Membrane Process $ % 5 Basic chemistry (must memorize equations): " 7 . . G %" Anode reaction: 2Cl (aq ) → Cl2 ( g ) + 2e − − − − . Cathode reaction: 2 H 2 O (l ) + 2e → H 2 ( g ) + 2OH ( aq) Overall: 2 NaCl ( aq) + 2 H 2 O (l )   → 2 NaOH ( aq) + Cl2 ( g ) + H 2 ( g )  electrolysis Technical and environmental difficulties in comparison to other processes: # • • • 5 G . . A 5 Model response: “Evaluate changes in industrial production methods for sodium hydroxide” (6 marks HSC2002) + # 1 G ( / 0 . 5 & # " G . * G -" # GH G - G To identify chlorine: , G> $ , % To identify hydrogen gas: , ,K 3 To identify NaOH: $ G Hazards: • 7 • 7 0 ! " , G - 9 1 3 The decomposition of molten NaCl to its elements: % , # # 2 NaCl (l ) → 2 Na (l ) + Cl 2 ( g ) Na + e → Na (l ) + − 2Cl − → Cl2 ( g ) + 2e − The decomposition of aqueous NaCl to its elements: * 2 NaCl (aq ) + 2 H 2O(l ) → 2 Na + (aq ) + 2OH − (aq) + H 2 ( g ) + Cl2 ( g ) % , # 2 H 2O + 2e − → H 2 + 2OH − 2Cl − → Cl2 ( g ) + 2e − # & B + Saponification is described as the hydrolysis of fats and oils under alkaline conditions (OH) to produce glycerol and salts of fatty acids. + . L -" L% -" . Ra − COO − Rb + OH − → Ra − COO − + Rb − OH For example: H . → H " Process in the school laboratory: , G Procedure: B 2 ) . > 7 * G% ! B . @ + Safety risk: • G • G . K 3 G% B** 2 . )* 2 ! *0 G >* > . G - Conditions: • 0 • • 1 + " . . K 3 . 1 . Industrial process: 0. G ) + 4 > ! 1 B @ 7 Conditions: • • • 0 + . $ 1 Comparison in summary: In the School lab: • 6 • 6 • + • ' • + . 0 Structure of soap: + " K 5 K 3 " 3 " . . K . 3 " K 3 Account for soap’s cleaning action: 7 5 5 5 . 5 . + 4 , 4 Model response: “describe the molecular structure of soap and use this structure to account for the cleaning action of soaps” 7 , 5 % 5 7 5 . 5 " " " . 4 ) , ! 4 4 Emulsion: the dispersion of small droplets of an immiscible liquid in another + . + Formation of micelles: 5 . # $ $ 5 % $ % $ % $ Anionic detergents: detergents which have a negative charged head. Eg. soap Cationic detergents: detergents with a positively charged head. Eg. alkyl ammonium group Non-ionic detergents: detergents with a polar head rather than ionic head groups such as alcohol and ethoxy functional groups. Surfactant: substance that decreases the surface tension of water or, alternatively, that ‘solubilises’ dirt and grease Structure and chemical compositions: + , + " , ( " G 5 " 2 L% 2 " L'L L + )L 2 4 . 5 % ( 2 " % G LG >H" ' %5 L L % G H" G H" L%-)L %-)L L" Effect in hard water and uses: 9 + , 8 . 0 )H % " )H" D 0 " , . $ 1 G 5 G 9 8 > + 4 % G 9 . % , $ & 5 % . , 6 % / 8 + • • • • • 2 & . #, " . . . # & # CH 3 (CH 2 )14 COOH + # CH 3 (CH 2 )16 COOH # CH 3 (CH 2 ) 7 − CH = CH − (CH 2 ) 7 COOH # CH 3 (CH 2 ) 4 − CH = CH − CH 2 − CH = CH − (CH 2 ) 7 COOH & & ! & Soaps: + . Early detergents: 9 . . . Recent detergents: 0 / " . 1 . . " AB* + K @* " % Non-ionic detergents: 0 5 ! Assessment/Judgment: , ' , 7 7 ( B + & @* G%" Raw materials: Products: , (CaCl3 ) # " (Na2CO3 ) • • • • • & 7 $ + 5 + , & % $ # . " #+ " #+ . # / #+ " % $ & & && # $ . . " . / % $ Flowchart: Sequence of steps in the Solvay process 6 G% " Chemistry of brine purification: B 6 $ # # 2− Ca 3+ (aq ) + CO3 (aq ) → CaCO3 ( s) . Mg 2+ (aq ) + 2OH − (aq ) → Mg (OH ) 2 ( s ) Fe 3+ (aq ) + 3OH − (aq ) → Fe(OH ) 3 ( s ) , ) > % . Chemistry of hydrogen carbonate formation: 7 . " % # ) CO2 ( g ) + H 2O (l ) ↔ H 2CO3 (aq ) " + − "# # NH 3 (aq ) + H 2CO3 (aq) ↔ NH 4 (aq ) + HCO3 (aq) Na (aq ) + HCO3 (aq ) ↔ NaHCO3 ( s ) # + − NaCl (aq ) + CO2 ( g ) + NH 3 ( g ) + H 2O (l ) → NaHCO3 ( s ) + NH 4Cl (aq ) ! Chemistry of sodium carbonate formation: 8 # 2 NaHCO3 ( s ) heat → Na 2CO3 ( s ) + CO2 ( g ) + H 2O ( g )   . B Chemistry of ammonia recovery: , . 2 . # + . " CaCO3 ( s ) → CaO ( s ) + CO2 ( g ) . # CaO ( s ) + H 2O(l ) → Ca (OH ) 2 (aq ) . Ammonia recovery: Ca (OH ) 2 ( aq ) + 2 NH 4Cl ( aq) → CaCl2 ( aq ) + 2 H 2O (l ) + 2 NH 3 ( g ) The overall reaction for the Solvay process: 2 NaCl (aq ) + CaCO3 ( s) ammonia → Na 2 CO3 ( s) + CaCl 2 (aq )   & & ! @ General statement: , + Thermal pollution: + . . . . Waste products: , + , Conclusion: 7 5 + How the issues are addressed: + , $ & 7 ,. 8 ! && & Procedure for modeling reaction of ammoniacal brine with carbon dioxide: D % ) : " . G% G !% G )% > Safety risks: % 9 ) & 5 , G> - Difficulties with laboratory modeling: $ $ 4 & & *% G> & ! G> - Criteria used: # ) L 1 . Example- the Solvay process: + 1 , 9 1 G% 4 1 F 8 . 1 1 .