JK-TK/Newdata huggingface dataset:
(a)Identify: (i)gas P Carbon(IV)oxide/CO2 (ii)Solid Q
38 Carbon/coke/charcoal (iii)Solid R Carbon/coke/charcoal (iv)Solid V Limestone/calcium carbonate/CaCO3 (v)Solid S Iron/Fe (b)Write the chemical equation for the reaction for the formation of: (i)Solid S Fe2O3(s) + 3CO(g) -> 2Fe(s) + 3CO2(g) (ii)Carbon(II)oxide C(s) + CO2 (g) -> 2CO (g) (iii)Slag SiO2(s) + CaO(s) -> CaSiO3(s) Al2O3 (s) + CaO(s) -> Ca Al2O4(s) (iv)Gas P C(s) + O2 (g) -> CO2 (g) (c)State two uses of: (i)Solid S Iron is used in making: (i)gates ,pipes, engine blocks, rails, charcoal iron boxes, lamp posts because it is cheap. (ii)nails, cutlery, scissors, sinks, vats, spanners, steel rods, and railway points from steel. Steel is an alloy of iron with carbon, and/or Vanadium, Manganese, Tungsten, Nickel ,Chromium. It does not rust/corrode like iron. (ii)Slag (i) tarmacing roads (ii) cement manufacture (iii) as building construction material 3.You are provided with sulphuric(VI)acid ,2M aqueous ammonia and two ores suspected to contain copper and iron. Describe with explanation how you would differentiate the two ores. Crush the two ores separately in using a mortar and pestle to reduce the particle size/increase the surface area. Add sulphuric(VI)acid to separate portion of the ore. Filter. 39 To a portion of the filtrate,add three drops of 2M aqueous ammonia then axcess Results A green precipitate insoluble in excess 2M aqueous ammonia confirms the ore contain Fe2+ ion. A brown precipitate insoluble in excess 2M aqueous ammonia confirms the ore contain Fe3+ ion. A blue precipitate that dissolve in excess 2M aqueous ammonia to form a deep/royal blue solution confirms the ore contain Cu2+ ion. 4.
A brown precipitate insoluble in excess 2M aqueous ammonia confirms the ore contain Fe3+ ion. A blue precipitate that dissolve in excess 2M aqueous ammonia to form a deep/royal blue solution confirms the ore contain Cu2+ ion. 4. Use the flow chart below showing the extraction of Zinc metal to answer the questions that follow (a)Name: (i)two ores from which Zinc can be extracted Calamine(ZnCO3) Zinc blende(ZnS) (ii)two possible identity of gas P Sulphur(IV)oxide(SO2) from roasting Zinc blende Carbon(IV)oxide(CO2) from decomposition of Calamine. (b)Write a possible chemical equation taking place in the roasting chamber. 2ZnS(s) + 3O2 (g) -> 2ZnO(s) + 2SO2(g) ZnCO3(s) -> ZnO(s) + CO2(g) (c)Explain the effect of the by-product of the roating on the environment. Sulphur (IV)oxide from roasting Zinc blende is an acidic gas that causes “acid rain” on dissolving in rain water. Carbon(IV)oxide(CO2) from decomposition of Calamine is a green house gas that causes global warming. (d)(i)Name a suitable reducing agent used in the furnace during extraction of Zinc. Carbon(II)oxide
40 (ii)Write a chemical equation for the reduction process ZnO(s) + CO(g) -> Zn(s) + CO2(g) (e)(i)Before electrolysis, the products from roasting is added dilute sulphuric (VI)acid. Write the equation for the reaction with dilute sulphuric(VI)acid. ZnO(s) + H2SO4 (aq) -> Zn SO4(aq) + H2(g) (ii)During the electrolysis for extraction of Zinc,state the I. Anode used Aluminium sheet II.
Write the equation for the reaction with dilute sulphuric(VI)acid. ZnO(s) + H2SO4 (aq) -> Zn SO4(aq) + H2(g) (ii)During the electrolysis for extraction of Zinc,state the I. Anode used Aluminium sheet II. Cathode used Lead plate coated with silver (ii)Write the equation for the electrolysis for extraction of Zinc at the: I.Cathode; Zn2+(aq) + 2e -> Zn(s) II.Anode; 4OH-(aq) -> 2H2O(l) + O2(s) + 4e (f)(i)What is galvanization Dipping Iron in molten Zinc to form a thin layer of Zinc to prevent iron from rusting. (ii)Galvanized iron sheet rust after some time. Explain The thin layer of Zinc protect Iron from rusting through sacrificial protection. When all the Zinc has reacted with elements of air, Iron start rusting. (g)State two uses of Zinc other than galvanization. Making brass(Zinc/copper alloy) Making german silver(Zinc/copper/nickel alloy) As casing for dry cells/battery (h)Calculate the mass of Zinc that is produced from the reduction chamber if 6400kg of Calamine ore is fed into the roaster.
When all the Zinc has reacted with elements of air, Iron start rusting. (g)State two uses of Zinc other than galvanization. Making brass(Zinc/copper alloy) Making german silver(Zinc/copper/nickel alloy) As casing for dry cells/battery (h)Calculate the mass of Zinc that is produced from the reduction chamber if 6400kg of Calamine ore is fed into the roaster. Assume the process is 80% efficient in each stage(Zn=64.0,C=12.0,O=16.0) Molar mass ZnCO3(s) =124g Molar mass Zn = 64g Molar mass ZnO = 80g Chemical equation ZnCO3(s) -> ZnO(s) + CO2(g) Method 1 124g ZnCO3 => 80g ZnO
41 (6400kg x1000)g ZnCO3 => (6400 x1000) x 80 = 512,000,000 g of ZnO 124 100% => 512,000,000 g of ZnO 80% => 80 x 512,000,000 g = 409600000g of ZnO 100 Chemical equation ZnO(s) + CO(g) -> Zn(s) + CO2(g) 80g ZnO(s) => 64g Zn(s) 409600000g of ZnO => 409600000g x 64 = 327680000 g Zn 80 100% => 327680000 g Zn 80% => 80 x 327680000 g Zn = 262144000g of Zn 100 Mass of Zinc produced = 262144000g of Zn 5.An ore is suspected to bauxite. Describe the process that can be used to confirm the presence of aluminium in the ore. Crush the ore to fine powder to increase surface area/reduce particle size. Add hot concentrated sulphuric(VI)/nitric(V) acid to free the ions. Filter. Retain the filtrate Add excess aqueous ammonia to a sample of filtrate. A white precipitate confirms presence of either Al3+ or Pb2+. Add sodium sulphate,dilute sulphuric(VI)to another portion of filtrate.
Retain the filtrate Add excess aqueous ammonia to a sample of filtrate. A white precipitate confirms presence of either Al3+ or Pb2+. Add sodium sulphate,dilute sulphuric(VI)to another portion of filtrate. No white precipitate confirms presence of Al3+ Or Add potassium iodide to another portion of filtrate. No yellow precipitate confirms presence of Al3+ 6.The flow chart below illustrate the industrial extraction of Lead metal
42 (a)(i)Name the chief ore that is commonly used in this process Galena(PbS) (ii)Explain what take place in the roasting furnace
23.0.0 ORGANIC CHEMISTRY II (ALKANOLS AND ALKANOIC ACIDS) (20 LESSONS) B.ALKANOLS(Alcohols) (A) INTRODUCTION.
Add sodium sulphate,dilute sulphuric(VI)to another portion of filtrate. No white precipitate confirms presence of Al3+ Or Add potassium iodide to another portion of filtrate. No yellow precipitate confirms presence of Al3+ 6.The flow chart below illustrate the industrial extraction of Lead metal
42 (a)(i)Name the chief ore that is commonly used in this process Galena(PbS) (ii)Explain what take place in the roasting furnace
23.0.0 ORGANIC CHEMISTRY II (ALKANOLS AND ALKANOIC ACIDS) (20 LESSONS) B.ALKANOLS(Alcohols) (A) INTRODUCTION. Alkanols belong to a homologous series of organic compounds with a general formula CnH2n +1 OH and thus -OH as the functional group .The 1st ten alkanols include n General / molecular formular Structural formula IUPAC name 1 CH3OH H – C –O - H │ H Methanol 2 CH3 CH2OH H H Ethanol
2 C2H5 OH H C – C –O - H │ H H 3 CH3 (CH2)2OH C3H7 OH H H H H C – C - C –O - H │ H H H Propanol 4 CH3 (CH2)3OH C4H9 OH H H H H H C – C - C - C –O - H │ H H H H Butanol 5 CH3(CH2)4OH C5H11 OH H H H H H H C – C - C- C- C –O - H │ H H H H H Pentanol 6 CH3(CH2)5OH C6H13 OH H H H H H H H C – C - C- C- C– C - O - H │ H H H H H H Hexanol 7 CH3(CH2)6OH C7H15 OH H H H H H H H H C – C - C- C- C– C –C- O - H │ H H H H H H H Heptanol 8 CH3(CH2)7OH C8H17 OH H H H H H H H H H C – C - C- C- C– C –C- C -O - H │ H H H H H H H H Octanol
3 9 CH3(CH2)8OH C9H19 OH H H H H H H H H H H C – C - C- C- C– C –C- C –C- O - H │ H H H H H H H H H Nonanol 10 CH3(CH2)9OH C10H21 OH H H H H H H H H H H H C – C - C- C- C– C –C- C –C- C-O - H │ H H H H H H H H H H Decanol Alkanols like Hydrocarbons( alkanes/alkenes/alkynes) form a homologous series where: (i)general name is derived from the alkane name then ending with “-ol” (ii)the members have –OH as the fuctional group (iii)they have the same general formula represented by R-OH where R is an alkyl group.
No white precipitate confirms presence of Al3+ Or Add potassium iodide to another portion of filtrate. No yellow precipitate confirms presence of Al3+ 6.The flow chart below illustrate the industrial extraction of Lead metal
42 (a)(i)Name the chief ore that is commonly used in this process Galena(PbS) (ii)Explain what take place in the roasting furnace
23.0.0 ORGANIC CHEMISTRY II (ALKANOLS AND ALKANOIC ACIDS) (20 LESSONS) B.ALKANOLS(Alcohols) (A) INTRODUCTION. Alkanols belong to a homologous series of organic compounds with a general formula CnH2n +1 OH and thus -OH as the functional group .The 1st ten alkanols include n General / molecular formular Structural formula IUPAC name 1 CH3OH H – C –O - H │ H Methanol 2 CH3 CH2OH H H Ethanol
2 C2H5 OH H C – C –O - H │ H H 3 CH3 (CH2)2OH C3H7 OH H H H H C – C - C –O - H │ H H H Propanol 4 CH3 (CH2)3OH C4H9 OH H H H H H C – C - C - C –O - H │ H H H H Butanol 5 CH3(CH2)4OH C5H11 OH H H H H H H C – C - C- C- C –O - H │ H H H H H Pentanol 6 CH3(CH2)5OH C6H13 OH H H H H H H H C – C - C- C- C– C - O - H │ H H H H H H Hexanol 7 CH3(CH2)6OH C7H15 OH H H H H H H H H C – C - C- C- C– C –C- O - H │ H H H H H H H Heptanol 8 CH3(CH2)7OH C8H17 OH H H H H H H H H H C – C - C- C- C– C –C- C -O - H │ H H H H H H H H Octanol
3 9 CH3(CH2)8OH C9H19 OH H H H H H H H H H H C – C - C- C- C– C –C- C –C- O - H │ H H H H H H H H H Nonanol 10 CH3(CH2)9OH C10H21 OH H H H H H H H H H H H C – C - C- C- C– C –C- C –C- C-O - H │ H H H H H H H H H H Decanol Alkanols like Hydrocarbons( alkanes/alkenes/alkynes) form a homologous series where: (i)general name is derived from the alkane name then ending with “-ol” (ii)the members have –OH as the fuctional group (iii)they have the same general formula represented by R-OH where R is an alkyl group. (iv) each member differ by –CH2 group from the next/previous.
No yellow precipitate confirms presence of Al3+ 6.The flow chart below illustrate the industrial extraction of Lead metal
42 (a)(i)Name the chief ore that is commonly used in this process Galena(PbS) (ii)Explain what take place in the roasting furnace
23.0.0 ORGANIC CHEMISTRY II (ALKANOLS AND ALKANOIC ACIDS) (20 LESSONS) B.ALKANOLS(Alcohols) (A) INTRODUCTION. Alkanols belong to a homologous series of organic compounds with a general formula CnH2n +1 OH and thus -OH as the functional group .The 1st ten alkanols include n General / molecular formular Structural formula IUPAC name 1 CH3OH H – C –O - H │ H Methanol 2 CH3 CH2OH H H Ethanol
2 C2H5 OH H C – C –O - H │ H H 3 CH3 (CH2)2OH C3H7 OH H H H H C – C - C –O - H │ H H H Propanol 4 CH3 (CH2)3OH C4H9 OH H H H H H C – C - C - C –O - H │ H H H H Butanol 5 CH3(CH2)4OH C5H11 OH H H H H H H C – C - C- C- C –O - H │ H H H H H Pentanol 6 CH3(CH2)5OH C6H13 OH H H H H H H H C – C - C- C- C– C - O - H │ H H H H H H Hexanol 7 CH3(CH2)6OH C7H15 OH H H H H H H H H C – C - C- C- C– C –C- O - H │ H H H H H H H Heptanol 8 CH3(CH2)7OH C8H17 OH H H H H H H H H H C – C - C- C- C– C –C- C -O - H │ H H H H H H H H Octanol
3 9 CH3(CH2)8OH C9H19 OH H H H H H H H H H H C – C - C- C- C– C –C- C –C- O - H │ H H H H H H H H H Nonanol 10 CH3(CH2)9OH C10H21 OH H H H H H H H H H H H C – C - C- C- C– C –C- C –C- C-O - H │ H H H H H H H H H H Decanol Alkanols like Hydrocarbons( alkanes/alkenes/alkynes) form a homologous series where: (i)general name is derived from the alkane name then ending with “-ol” (ii)the members have –OH as the fuctional group (iii)they have the same general formula represented by R-OH where R is an alkyl group. (iv) each member differ by –CH2 group from the next/previous. (v)they show a similar and gradual change in their physical properties e.g.
Alkanols belong to a homologous series of organic compounds with a general formula CnH2n +1 OH and thus -OH as the functional group .The 1st ten alkanols include n General / molecular formular Structural formula IUPAC name 1 CH3OH H – C –O - H │ H Methanol 2 CH3 CH2OH H H Ethanol
2 C2H5 OH H C – C –O - H │ H H 3 CH3 (CH2)2OH C3H7 OH H H H H C – C - C –O - H │ H H H Propanol 4 CH3 (CH2)3OH C4H9 OH H H H H H C – C - C - C –O - H │ H H H H Butanol 5 CH3(CH2)4OH C5H11 OH H H H H H H C – C - C- C- C –O - H │ H H H H H Pentanol 6 CH3(CH2)5OH C6H13 OH H H H H H H H C – C - C- C- C– C - O - H │ H H H H H H Hexanol 7 CH3(CH2)6OH C7H15 OH H H H H H H H H C – C - C- C- C– C –C- O - H │ H H H H H H H Heptanol 8 CH3(CH2)7OH C8H17 OH H H H H H H H H H C – C - C- C- C– C –C- C -O - H │ H H H H H H H H Octanol
3 9 CH3(CH2)8OH C9H19 OH H H H H H H H H H H C – C - C- C- C– C –C- C –C- O - H │ H H H H H H H H H Nonanol 10 CH3(CH2)9OH C10H21 OH H H H H H H H H H H H C – C - C- C- C– C –C- C –C- C-O - H │ H H H H H H H H H H Decanol Alkanols like Hydrocarbons( alkanes/alkenes/alkynes) form a homologous series where: (i)general name is derived from the alkane name then ending with “-ol” (ii)the members have –OH as the fuctional group (iii)they have the same general formula represented by R-OH where R is an alkyl group. (iv) each member differ by –CH2 group from the next/previous. (v)they show a similar and gradual change in their physical properties e.g. boiling and melting points.
(iv) each member differ by –CH2 group from the next/previous. (v)they show a similar and gradual change in their physical properties e.g. boiling and melting points. (vi)they show similar and gradual change in their chemical properties. B. ISOMERS OF ALKANOLS. Alkanols exhibit both structural and position isomerism. The isomers are named by using the following basic guidelines: (i)Like alkanes , identify the longest carbon chain to be the parent name. (ii)Identify the position of the -OH functional group to give it the smallest /lowest position. (iii) Identify the type and position of the side branches. Practice examples of isomers of alkanols (i)Isomers of propanol C3H7OH CH3CH2CH2OH - Propan-1-ol OH CH3CHCH3 - Propan-2-ol
4 Propan-2-ol and Propan-1-ol are position isomers because only the position of the –OH functional group changes. (ii)Isomers of Butanol C4H9OH CH3 CH2 CH3 CH2 OH Butan-1-ol CH3 CH2 CH CH3 OH Butan-2-ol CH3 CH3 CH3 CH3 OH 2-methylpropan-2-ol Butan-2-ol and Butan-1-ol are position isomers because only the position of the -OH functional group changes. 2-methylpropan-2-ol is both a structural and position isomers because both the position of the functional group and the arrangement of the atoms in the molecule changes.
Practice examples of isomers of alkanols (i)Isomers of propanol C3H7OH CH3CH2CH2OH - Propan-1-ol OH CH3CHCH3 - Propan-2-ol
4 Propan-2-ol and Propan-1-ol are position isomers because only the position of the –OH functional group changes. (ii)Isomers of Butanol C4H9OH CH3 CH2 CH3 CH2 OH Butan-1-ol CH3 CH2 CH CH3 OH Butan-2-ol CH3 CH3 CH3 CH3 OH 2-methylpropan-2-ol Butan-2-ol and Butan-1-ol are position isomers because only the position of the -OH functional group changes. 2-methylpropan-2-ol is both a structural and position isomers because both the position of the functional group and the arrangement of the atoms in the molecule changes. (iii)Isomers of Pentanol C5H11OH CH3 CH2 CH2CH2CH2 OH Pentan-1-ol (Position isomer) CH3 CH2 CH CH3 OH Pentan-2-ol (Position isomer) CH3 CH2 CH CH2 CH3 OH Pentan-3-ol (Position isomer) CH3 CH3 CH2 CH2 C CH3
5 OH 2-methylbutan-2-ol (Position /structural isomer) CH3 CH3 CH2 CH2 C CHOH CH3 2,2-dimethylbutan-1-ol (Position /structural isomer) CH3 CH3 CH2 CH C CH3 CH3 OH 2,3-dimethylbutan-1-ol (Position /structural isomer) (iv)1,2-dichloropropan-2-ol CClH2 CCl CH3 OH (v)1,2-dichloropropan-1-ol CClH2 CHCl CH2 OH (vi) Ethan1,2-diol H H HOCH2CH2OH H-O - C - C – O-H H H (vii) Propan1,2,3-triol H OH H HOCH2CHOHCH2OH H-O - C- C – C – O-H H H H C. LABORATORY PREPARATION OF ALKANOLS.
2-methylpropan-2-ol is both a structural and position isomers because both the position of the functional group and the arrangement of the atoms in the molecule changes. (iii)Isomers of Pentanol C5H11OH CH3 CH2 CH2CH2CH2 OH Pentan-1-ol (Position isomer) CH3 CH2 CH CH3 OH Pentan-2-ol (Position isomer) CH3 CH2 CH CH2 CH3 OH Pentan-3-ol (Position isomer) CH3 CH3 CH2 CH2 C CH3
5 OH 2-methylbutan-2-ol (Position /structural isomer) CH3 CH3 CH2 CH2 C CHOH CH3 2,2-dimethylbutan-1-ol (Position /structural isomer) CH3 CH3 CH2 CH C CH3 CH3 OH 2,3-dimethylbutan-1-ol (Position /structural isomer) (iv)1,2-dichloropropan-2-ol CClH2 CCl CH3 OH (v)1,2-dichloropropan-1-ol CClH2 CHCl CH2 OH (vi) Ethan1,2-diol H H HOCH2CH2OH H-O - C - C – O-H H H (vii) Propan1,2,3-triol H OH H HOCH2CHOHCH2OH H-O - C- C – C – O-H H H H C. LABORATORY PREPARATION OF ALKANOLS. For decades the world over, people have been fermenting grapes juice, sugar, carbohydrates and starch to produce ethanol as a social drug for relaxation. 6 In large amount, drinking of ethanol by mammals /human beings causes mental and physical lack of coordination. Prolonged intake of ethanol causes permanent mental and physical lack of coordination because it damages vital organs like the liver. Fermentation is the reaction where sugar is converted to alcohol/alkanol using biological catalyst/enzymes in yeast. It involves three processes: (i)Conversion of starch to maltose using the enzyme diastase.
Prolonged intake of ethanol causes permanent mental and physical lack of coordination because it damages vital organs like the liver. Fermentation is the reaction where sugar is converted to alcohol/alkanol using biological catalyst/enzymes in yeast. It involves three processes: (i)Conversion of starch to maltose using the enzyme diastase. (C6H10O5)n (s) + H2O(l) --diastase enzyme --> C12H22O11(aq) (Starch) (Maltose) (ii)Hydrolysis of Maltose to glucose using the enzyme maltase. C12H22O11(aq)+ H2O(l) -- maltase enzyme -->2 C6H12O6(aq) (Maltose) (glucose) (iii)Conversion of glucose to ethanol and carbon(IV)oxide gas using the enzyme zymase. C6H12O6(aq) -- zymase enzyme --> 2 C2H5OH(aq) + 2CO2(g) (glucose) (Ethanol) At concentration greater than 15% by volume, the ethanol produced kills the yeast enzyme stopping the reaction. To increases the concentration, fractional distillation is done to produce spirits (e.g. Brandy=40% ethanol). Methanol is much more poisonous /toxic than ethanol. Taken large quantity in small quantity it causes instant blindness and liver, killing the consumer victim within hours. School laboratory preparation of ethanol from fermentation of glucose Measure 100cm3 of pure water into a conical flask. Add about five spatula end full of glucose. Stir the mixture to dissolve. Add about one spatula end full of yeast. Set up the apparatus as below. 7 Preserve the mixture for about three days. D.PHYSICAL AND CHEMICAL PROPERTIES OF ALKANOLS Use the prepared sample above for the following experiments that shows the characteristic properties of alkanols (a) Role of yeast Yeast is a single cell fungus which contains the enzyme maltase and zymase that catalyse the fermentation process. (b) Observations in lime water. A white precipitate is formed that dissolve to a colourless solution later. Lime water/Calcium hydroxide reacts with carbon(IV)0xide produced during the fermentation to form insoluble calcium carbonate and water.
(b) Observations in lime water. A white precipitate is formed that dissolve to a colourless solution later. Lime water/Calcium hydroxide reacts with carbon(IV)0xide produced during the fermentation to form insoluble calcium carbonate and water. More carbon (IV)0xide produced during fermentation react with the insoluble calcium carbonate and water to form soluble calcium hydrogen carbonate. Ca(OH)2(aq) + CO2 (g) -> CaCO3(s) H2O(l) + CO2 (g) + CaCO3(s) -> Ca(HCO3) 2 (aq) (c)Effects on litmus paper Experiment
8 Take the prepared sample and test with both blue and red litmus papers. Repeat the same with pure ethanol and methylated spirit. Sample Observation table Substance/alkanol Effect on litmus paper Prepared sample Blue litmus paper remain blue Red litmus paper remain red Absolute ethanol Blue litmus paper remain blue Red litmus paper remain red Methylated spirit Blue litmus paper remain blue Red litmus paper remain red Explanation Alkanols are neutral compounds/solution that have characteristic sweet smell and taste. They have no effect on both blue and red litmus papers. (d)Solubility in water. Experiment Place about 5cm3 of prepared sample into a clean test tube Add equal amount of distilled water. Repeat the same with pure ethanol and methylated spirit. Observation No layers formed between the two liquids. Explanation Ethanol is miscible in water.Both ethanol and water are polar compounds . The solubility of alkanols decrease with increase in the alkyl chain/molecular mass. The alkyl group is insoluble in water while –OH functional group is soluble in water. As the molecular chain becomes longer ,the effect of the alkyl group increases as the effect of the functional group decreases. e)Melting/boiling point. Experiment Place pure ethanol in a long boiling tube .Determine its boiling point. Observation Pure ethanol has a boiling point of 78oC at sea level/one atmosphere pressure. Explanation The melting and boiling point of alkanols increase with increase in molecular chain/mass . 9 This is because the intermolecular/van-der-waals forces of attraction between the molecules increase. More heat energy is thus required to weaken the longer chain during melting and break during boiling.
Explanation The melting and boiling point of alkanols increase with increase in molecular chain/mass . 9 This is because the intermolecular/van-der-waals forces of attraction between the molecules increase. More heat energy is thus required to weaken the longer chain during melting and break during boiling. f)Density Density of alkanols increase with increase in the intermolecular/van-der-waals forces of attraction between the molecule, making it very close to each other. This reduces the volume occupied by the molecule and thus increase the their mass per unit volume (density). Summary table showing the trend in physical properties of alkanols Alkanol Melting point (oC) Boiling point (oC) Density gcm-3 Solubility in water Methanol -98 65 0.791 soluble Ethanol -117 78 0.789 soluble Propanol -103 97 0.803 soluble Butanol -89 117 0.810 Slightly soluble Pentanol -78 138 0.814 Slightly soluble Hexanol -52 157 0.815 Slightly soluble Heptanol -34 176 0.822 Slightly soluble Octanol -15 195 0.824 Slightly soluble Nonanol -7 212 0.827 Slightly soluble Decanol 6 228 0.827 Slightly soluble g)Burning Experiment Place the prepared sample in a watch glass. Ignite. Repeat with pure ethanol and methylated spirit. Observation/Explanation Fermentation produce ethanol with a lot of water(about a ratio of 1:3)which prevent the alcohol from igniting. Pure ethanol and methylated spirit easily catch fire / highly flammable. They burn with an almost colourless non-sooty/non-smoky blue flame to form carbon(IV) oxide (in excess air/oxygen)or carbon(II) oxide (limited air) and water. Ethanol is thus a saturated compound like alkanes.
Pure ethanol and methylated spirit easily catch fire / highly flammable. They burn with an almost colourless non-sooty/non-smoky blue flame to form carbon(IV) oxide (in excess air/oxygen)or carbon(II) oxide (limited air) and water. Ethanol is thus a saturated compound like alkanes. 10 Chemica equation C2 H5OH(l) + 3O2 (g) -> 3H2O(l) + 2CO2 (g) ( excess air) C2 H5OH(l) + 2O2 (g) -> 3H2O(l) + 2CO (g) ( limited air) 2CH3OH(l) + 3O2 (g) -> 4H2O(l) + 2CO2 (g) ( excess air) 2 CH3OH(l) + 2O2 (g) -> 4H2O(l) + 2CO (g) ( limited air) 2C3 H7OH(l) + 9O2 (g) -> 8H2O(l) + 6CO2 (g) ( excess air) C3 H7OH(l) + 3O2 (g) -> 4H2O(l) + 3CO (g) ( limited air) 2C4 H9OH(l) + 13O2 (g) -> 20H2O(l) + 8CO2 (g) ( excess air) C4 H9OH(l) + 3O2 (g) -> 4H2O(l) + 3CO (g) ( limited air) Due to its flammability, ethanol is used; (i) as a fuel in spirit lamps (ii) as gasohol when blended with gasoline (h)Formation of alkoxides Experiment Cut a very small piece of sodium. Put it in a beaker containing about 20cm3 of the prepared sample in a beaker. Test the products with litmus papers. Repeat with absolute ethanol and methylated spirit.