1)Change of ethanol to ethane
What is the name of this reaction?
• Dehydration reaction
How do you test the presence of ethene?
• Collect the gas in a test tube• Pour some solution of
bromine• Shake hard• The brown bromine is
decolourised
c)What is the function of porcelain chips?
• Act as catalyst /dehydrating agent
Write chemical equation for heating of ethanol in porcelain chips
C2H5OH C2H4 + H2O
e)State 2 physical properties of ethanol
• 1) colourless liquid at room temperature
• 2)highly volatile• 3)soluble in water• 4) low melting point and boiling
point
g) If propanol is heated over the porcelain chips to replace ethanol,
state the gas that could be collected
Propene gas
Oxidation of ethanol to ethanoic acid
a) What is the name of this reaction?.
• Oxidation reaction
b) State observations in the boiling tube
• The colour of acidified potassium dichromate (VI) solution change from orange to green
c) What is the function of Acidified potassium dichromate(VI) solution?
As oxidising agent
d) Write chemical equation
C2H5OH + 2[O]
CH3COOH+ H2O
E) Name the distillate formed
• Ethanoic acid
f)Draw structural formula of the distillate
g)State 2 chemical properties of distillate formed
• 1) reacts with alcohol to form ester and water
• 2)reacts with alkali/base to produce salt and water
• 3)react with metal to produce salt and hydrogen gas
• 4)react with metal carbonate to produce salt , carbon dioxide and water
Name structures below and state homologous series and general
formula
n- butane
2-methylbutane
AlkaneCn H2n+2
AlkaneCn H2n+2
propene
2-butene/but-2-ene
AlkeneCn H2n
AlkeneCn H2n
3-butanol/butan-3-ol
Propanoic acid
AlcoholCn H2n+1OH
Carboxylic acidCn H2n+1 COOH
Ethyl propanoate esterCn H2n +1 COO CmH2m+1
If Z is zinc metal, Y is lead metal and X is copper metal,State observations in
the boiling tube •Z burns brightly leaving solid -yellow when hot, white when cold•Y burns less brightly leaving solid- brown when hot and yellow when cold •X burns slowly leaving black solid
• What is the function of Potassium manganate (VII) ?
• What is the function of glass wool?
•To provide oxygen gas when heated
•To prevent KMnO4 from mixing with metal and to avoid explosion from occuring
•Write chemical equation for reaction in the tube with Z metal
•From d) above, what substance is oxidized?, explain your answer
Z + O2 ZO or Zn + O2 ZnO
•Z or zinc is oxidised-oxidation number of zinc increase from 0 to +2 ORZ gain oxygen to form ZO
State 2 chemical properties of Z oxide formed
•Reacts with acid to form salt and water •Reacts with alkali to form salt and water
•This is because zinc oxide is an amphotheric oxide
Mark cathode and anode
Cathode
Anode
State observations at cathode and at anode
• At cathode
Iron spoon is plated white shiny deposit • At anode
Silver electrode corrodes/ becomes smaller
Write half equation at cathode and at anode
• At cathode
Ag + e Ag
• At anode
+
Ag Ag + e+
State observations at cathode and at anode
• At cathode
Iron spoon is plated white shiny deposit • At anode
Silver electrode corrodes/ becomes smaller
If the iron spoon is to be coated with copper, state object used at cathode and object at anode and electrolyte used • At cathode Iron spoon
• At anode Copper electrode
• electrolyte Copper (II) sulphate or copper(II) nitrate
• State substance to be used to keep latex coagulate fast
• State substance to be used to keep latex in liquid form
• Vulcanized rubber is formed when X is added to dry latex What is X?
Ethanoic acid
Ammonia solution
Sulphur 0r solution of disulphur monochloride in methyl benzene
Explain how the addition of substance X improve the property of natural rubber
Addition of sulphur forms cross-link (bridges) between long-chain molecules (rubber polymers)
State 3 better properties of vulcanized rubber compared to the unvulcanised ones
•Harder and stronger•More elastic•More resistant toward oxidation by air•Higher tensile strength•Has higher melting point( so can withstand high temperature)
reaction Name of catalyst1) Hydrogenation of ethene to ethane2) Decomposition of hydrogen peroxide3) Reaction of sulphuric acid with zinc
Nickel or platinum
Manganese(IV) oxide
Copper(II) sulphate (aq)
reaction Name of catalyst1) Change of SO2 to SO3 in contact process2) Haber process
3)Esterification reaction4) Alkene to alkane
Nickel or platinum
Vanadium(V) oxide
Iron
Concentrated H2SO4
reaction Name of catalyst1) Alkene to alcohol
2) Dehydration reaction of ethanol to ethene3) Glucose to ethanol
Phosphoric acid
Porcelain chips or Al2O3
yeast