Ethene Experiment(Complete) Flashcards
What is the formula for ethene?
C2H4.
What is the general formula for an alkene?
CnH2n
What is a functional group?
A group of atoms which give the homologous series its main characteristics.
What is the functional group of ethene?
C=C.
What is an isomer?
Same molecular formula but different structural formulae.
Why do isomers occur?
Due to different positions of the double bond.
Due to branching.
What its an unsaturated hydrocarbon?
Unsaturated: Contains one or more double or triple carbon to carbon bonds.
Hydrocarbon: Consists of hydrogen and carbon only.
Describe alkenes in terms of solubility.
Alkenes are non-polar.
Alkenes cannot dissolve in water as water is polar and alkenes are non polar.
Alkenes are soluble in non-polar solvents , e.g Octane, benzene, cyclohexane.
How do you produce ethene industrially?
By catalytic cracking of long chains alkanes.
C10H22= C2H4 + C5H12 + C3H6
Why is catalytic cracking done in oil refineries?
As the separating equipment/ apparatus is there.
Raw materials are there.
How do you produce ethene in a laboratory?
Dehydrating ethanol.
C2H5OH= C2H4 +H2O
Draw a diagram showing the production of ethene.
Diagram in manual.
What is the purpose of the bunsen burner?
To heat the aluminium oxide strongly.
What is the purpose of aluminium oxide?
To act as a catalyst/ dehydrating agent.
What is the appearance of aluminium oxide?
White powder.
What is the purpose of the glass wool?
To hold the ethanol in place to prevent it from reaching the aluminium oxide.
How do you collect ethene?
Over water as ethene is non polar and therefore cannot dissolve in water as water is polar.
Name 3 precautions used when carrying out the ethene experiment.
Remove the delivery tube before heating has stopped to prevent suck- back and explosion.
Wear protective goggles to prevent glass from going into your eye.
Wear a lab coat to prevent chemicals from leaking onto your clothes.
How is ethene formed?
By an elimination reaction involving ethanol.
Water is removed and a c=c double bond forms.
Dehydration reaction as water is removed.
What are the main characteristics of ethene?
Non polar.
Colourless.
Sweet smell.
Burns with oxygen to form carbon dioxide and water.
Produces a yellow non smoky flame when heated.
Give the equation of the heat of combustion of ethene.
C2H4 + 3O2 =2CO2 + 2H2O
How do you prove that ethene is unsaturated?
Shake with bromine water- tuns from red/brown to colourless.
Shake with acidified KMNO4- turns from pink to colourless.
Give one major use of ethene.
Ripening fruit or making polythene.