Effect of Zoe and Caoh Iodoform on Delaying Root Resopstion in Primary Molars
Iodoform Slides
Transcript of Iodoform Slides
The Iodoform Reaction The Iodoform Reaction
► ►Iodoform Iodoform – – Tri Tri iodomethane iodomethane ► ►CHI CHI 3 3
The Iodoform Reaction The Iodoform Reaction
iodomethane iodomethane
CCEA MODULE 2 CCEA MODULE 2
► ►2.6.11 2.6.11 Prepare iodoform and know its use to Prepare iodoform and know its use to distinguish between alcohols distinguish between alcohols containing CH containing CH CH(OH) and other CH(OH) and other containing CH containing CH 3 3 CH(OH) and other CH(OH) and other alcohols with specific reference to alcohols with specific reference to recrystallisation and melting points. recrystallisation and melting points.
CCEA MODULE 2 CCEA MODULE 2
Prepare iodoform and know its use to Prepare iodoform and know its use to distinguish between alcohols distinguish between alcohols
CH(OH) and other CH(OH) and other CH(OH) and other CH(OH) and other alcohols with specific reference to alcohols with specific reference to recrystallisation and melting points. recrystallisation and melting points.
Iodoform Reaction Iodoform Reaction
► ►The reaction occurs only with alcohols The reaction occurs only with alcohols containing the group. containing the group. CH CH 3 3 CH(R)OH CH(R)OH
► ►Works for all secondary alcohols and Works for all secondary alcohols and ► ►Works for all secondary alcohols and Works for all secondary alcohols and ethanol. ethanol.
► ►Or carbonyl compounds containing the Or carbonyl compounds containing the CH CH 2 2 CO CO group group
Iodoform Reaction Iodoform Reaction
The reaction occurs only with alcohols The reaction occurs only with alcohols containing the group. containing the group.
Works for all secondary alcohols and Works for all secondary alcohols and Works for all secondary alcohols and Works for all secondary alcohols and
Or carbonyl compounds containing the Or carbonyl compounds containing the
Iodoform as a Test for Secondary Iodoform as a Test for Secondary Alcohols Alcohols
► ►Add a solution of Add a solution of iodine in potassium iodide to an iodine in potassium iodide to an appropriate amount of alcohol. appropriate amount of alcohol.
► ► Followed Followed by sodium hydroxide by sodium hydroxide sodium sodium hypochlorite solution. hypochlorite solution.
► ►Alcohols with the group CH Alcohols with the group CH will form a yellow precipitate with an antiseptic will form a yellow precipitate with an antiseptic smell of tri smell of tri iodomethane CHI iodomethane CHI
The precipitate is filtered under suction. The precipitate is filtered under suction.
Iodoform as a Test for Secondary Iodoform as a Test for Secondary Alcohols Alcohols iodine in potassium iodide to an iodine in potassium iodide to an
appropriate amount of alcohol. appropriate amount of alcohol. by sodium hydroxide by sodium hydroxide solution and solution and hypochlorite solution. hypochlorite solution.
Alcohols with the group CH Alcohols with the group CH 3 3 CH(R)OH CH(R)OH will form a yellow precipitate with an antiseptic will form a yellow precipitate with an antiseptic
iodomethane CHI iodomethane CHI 3 3 . .
The precipitate is filtered under suction. The precipitate is filtered under suction.
► ►Carbonyl compounds with the group Carbonyl compounds with the group CH CH 2 2 CO (e.g. propanone CH CO (e.g. propanone CH the practical in the video) will also form a the practical in the video) will also form a yellow precipitate with an antiseptic smell of yellow precipitate with an antiseptic smell of yellow precipitate with an antiseptic smell of yellow precipitate with an antiseptic smell of tri tri iodomethane CHI iodomethane CHI 3 3 . .
The precipitate is filtered under suction. The precipitate is filtered under suction.
Carbonyl compounds with the group Carbonyl compounds with the group CO (e.g. propanone CH CO (e.g. propanone CH 3 3 COCH COCH 3 3 used in used in
the practical in the video) will also form a the practical in the video) will also form a yellow precipitate with an antiseptic smell of yellow precipitate with an antiseptic smell of yellow precipitate with an antiseptic smell of yellow precipitate with an antiseptic smell of
. .
The precipitate is filtered under suction. The precipitate is filtered under suction.
Suction Filtration Suction Filtration
NB: that suction filtration is used because it is quicker
Set up the filter pump (for suction filtration) and collect the yellow crystals.
Suction Filtration Suction Filtration
that suction filtration is used because it is quicker
Set up the filter pump (for suction filtration) and collect the yellow crystals.
Recrystallisation Recrystallisation P Purification of a Solid urification of a Solid
• • Dissolve Dissolve the the crude crude product product amount amount of of hot hot solvent solvent saturated saturated solution solution. .
• • Let Let the the hot hot saturated saturated Crystals Crystals will will form form. .
• • Filter Filter off off the the crystals crystals filtration filtration in in a a Buchner Buchner
Recrystallisation Recrystallisation urification of a Solid urification of a Solid
product product in in a a minimum minimum solvent solvent to to form form a a hot hot
saturated saturated solution solution cool cool slowly slowly. .
crystals crystals – – using using suction suction Buchner Buchner funnel funnel. .
Drying in a dessicator Drying in a dessicator
► ► Allow the crystals to dry in a dessicator Allow the crystals to dry in a dessicator
Drying in a dessicator Drying in a dessicator
Allow the crystals to dry in a dessicator Allow the crystals to dry in a dessicator
Recording the mass Recording the mass
► ►Record the mass of the collected Iodoform Record the mass of the collected Iodoform crystals and use the equation below to work crystals and use the equation below to work out the percentage yield. out the percentage yield.
► ►Percentage yield = Percentage yield = actual mass actual mass theoretical mass theoretical mass
Referring to practical and theoretical Referring to practical and theoretical considerations, why is the % yield not considerations, why is the % yield not 100%? 100%?
Recording the mass Recording the mass
Record the mass of the collected Iodoform Record the mass of the collected Iodoform crystals and use the equation below to work crystals and use the equation below to work out the percentage yield. out the percentage yield.
actual mass actual mass x 100 x 100 theoretical mass theoretical mass
Referring to practical and theoretical Referring to practical and theoretical considerations, why is the % yield not considerations, why is the % yield not
Why is the Percentage Yield Why is the Percentage Yield not 100%? not 100%?
► ►Practical: Practical: Loss during transfer Loss during transfer Loss during filtration and Loss during filtration and recrystallisation recrystallisation
► ►Theoretical Theoretical ► ►Theoretical Theoretical Side reactions Side reactions Reaction may not go to Reaction may not go to completion. completion.
Why is the Percentage Yield Why is the Percentage Yield not 100%? not 100%? Loss during transfer Loss during transfer Loss during filtration and Loss during filtration and recrystallisation recrystallisation
Side reactions Side reactions Reaction may not go to Reaction may not go to completion. completion.
Testing Purity Testing Purity
► ►The The melting melting point point guide guide to to its its purity purity identifying identifying the the solid solid. .
► ►Usually Usually a a pure pure substance substance ► ►Usually Usually a a pure pure substance substance range range of of 1 1 o o C C ii. .e e. . it it has has point point. .
► ►Pure Pure Iodoform Iodoform has has point point at at 119 119 o o C C. .
Testing Purity Testing Purity
of of a a solid solid is is a a good good purity purity and and may may be be used used for for
substance substance will will melt melt over over a a substance substance will will melt melt over over a a has has a a sharp sharp melting melting
has has a a sharp sharp melting melting
Taking Melting Point Taking Melting Point
• • A A melting melting point point tube tube is is • • The The substance substance is is crushed crushed end end of of a a melting melting point point or or with with a a pestle pestle in in a a clean clean or or with with a a pestle pestle in in a a clean clean
• • The The crushed crushed solid solid is is about about 2 2cm cm in in a a melting melting one one end end. .
Taking Melting Point Taking Melting Point
is is sealed sealed at at one one end end. . crushed crushed with with the the sealed sealed
point point tube tube on on a a filter filter paper paper clean clean mortar mortar. . clean clean mortar mortar. . placed placed to to a a depth depth of of
melting melting point point tube tube closed closed at at
• • The The tube tube is is then then placed placed apparatus apparatus and and heated heated
• • The The temperature temperature is is crystals crystals collapse collapse to to a a crystals crystals collapse collapse to to a a
• • A A pure pure solid solid gives gives POINT POINT. .
• • Impurities Impurities lower lower the the
placed placed in in the the melting melting point point heated heated. .
is is recorded recorded when when the the clear clear liquid liquid. . clear clear liquid liquid. . a a SHARP SHARP MELTING MELTING
the the melting melting point point. .