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What type of atoms are present in the fused ring structure of heterocyclic polynuclear compounds?
What is the study of stereoisomers known as?
What is a chirality center?
What is the term for isomers that contain chirality centers?
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What do stereoisomers differ in?
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What is the term for the study of the spatial arrangement of atoms in molecules?
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What is enantiomeric excess used to quantify?
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What is the formula to calculate enantiomeric excess?
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What is the correct configuration of the molecule with two CH3 groups on the same side of the double bond?
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What is the term used to describe the geometric isomers of an alkene with one substituent on each carbon?
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Why can't you directly translate cis- and trans- into (Z)- and (E)-?
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What is the optical rotation of a sample of a mixture of R and S carvone that has an enantiomeric excess of 20%?
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What is the purpose of both the cis-trans and (Z)-(E) systems?
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What is the specific rotation of (S)-(+)-2-bromobutane?
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What is the type of isomerism exhibited by 1-ethyl-3-methylcyclobutane?
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What should you do when converting between the cis-trans and (Z)-(E) systems?
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Why is the cis-trans system only suitable for very straightforward molecules?
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What happens when you assume that you can directly convert between the cis-trans and (Z)-(E) systems?
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What does a levorotatory compound do to the plane of polarization?
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What do the prefixes 'dextro' and 'levo' mean in Latin?
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What is the function of a polarimeter?
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What is the unit of measurement for specific rotation?
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What is the symbol used to indicate specific rotation?
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At what temperature is specific rotation normally measured?
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What is a characteristic of aromatic compounds?
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What is the definition of heterocyclic compounds?
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What is the name of the compounds containing more than one benzene ring?
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Why is carbon able to form a large number of compounds?
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What is the number of organic compounds that exceed a certain number?
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What is one of the unique properties of carbon?
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----- is when organic compounds are synthesized from living things using vital force.
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What year and who created urea
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What is a branch of study that deals with the study of carbons,nitrogen,hydrogen,and halogen compounds except cynate,Ho cynate and silicon
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What is the ability for carbon to form a bond a bond with other elements or itself
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Carbon= 1s²,2s²,2p². 1s² can take part in the reaction because it is very close to tge nucleus
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Process whereby electron is transferred from the lowest level to the highest level
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Process whereby two or more atomic orbital reacts to form a newly hybridized one
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Most important organic bond is called?
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Types of covalent bonds
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What is a very strong bond and cannot be easily broken and doesnt take part in organjc reactions
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What type of bond is a very weak bond and can easily be broken,also takes part in organic reactions
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The process whereby s orbital reacts to p orbital to create neither S nor P orbital is called?
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Types of hybridization
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Sp³,Sp²,Sp are types of hybridization
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Type of hybridization that occurs when s- orbital reacts with 3p's(px,py&pz) leaving none hybridized.
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What hybridization only occurs in single bond,alkane,has 109.5° or 109.28° and is tetrahedral in shape
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S+ px+py+pz=
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What type of hybridization occurs when s- orbitals reacts with 2ps(px&py) leaving one p (pz)unhybridized.
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Type of hybridization that Occurs in double compounda e.g alkene,trigonal in shape with an angle of 180°
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Hybridization that occurs when s-orbital reacts with one p(px) leaving two p's unhybridized (py&pz).
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Type of hybridization that occurs in triple bonds,alkyne,linear in shape with an angle of 180°
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S+px+py=
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S+px=
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State the terms used in hybridization
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The distance between two atoms in an organic compound or reaction is called?
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The higher the distance the higher rhe bond strength
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The process whereby an element accepts or attracts electron towards itself in order to become negatively charged is called?
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The lower the pie electron the higher the electronegativity
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Sp>Sp²>Sp3 does electronegativity decreases or increases?
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The amount of energy required to break the bond in an organic compound is called?
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The shorter the distance,the stronger the bond and vice versa
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Sp>Sp²>Sp³ bond strength increases or decreases?
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The higher the pie bond,the higher the reactivity
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Percentage of s character
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Percentage of p- character
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----------is the existence of two or more compounds having the same molecular formular but different strutural formula
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Typse of isomerism
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Constitutional isomerisim is also known as?
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Isomers tgat differs in the way that their atoms are attached/connected,i.e joined together is called?
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Isomers thqt their atoms are arranged in space are called?
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The study of of three dimensional structure of molecules is called?
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Types of stereoisomers
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Type of streoisomers that results in the rotation of c-c single bond is called?
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Amine inversion/umberalla effect is ?
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Conformers that interconvert rapidly at room temp thus cant be seperated is called?
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Type of stereo isomers that do not interconver and can be easily seperated is called?
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Tyeos of configurational Isomers
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Enantiomers are also known as?
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Enantiomers contaim chirality centers
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Types of structural isomers
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Optical isomers are also known as?
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an atom that has four different groups bonded to it in such a manner that it has a nonsuperimposable mirror image is called
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A compound containing a chirality centre can exist as two different isomers. The two isomers cannot be super imposed. Just as you cannot super impose your left hand on your right hand
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Isomers that are nonidentical (nonsuperimposable) mirror image are called?
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(Enantiomers is from the Greek word called and it means what?
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A molecule that has a nonidentical mirror image is said to be?
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A chiral molecule does not contain a plane of symmetry.
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Aplane that cuts a molecule into two halves, each of which is a mirror image of the other.
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Chiral objects do not contain a plane of symmetry
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molecule containing a plane of symmetry is?
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A chirality centre is what cause a molecule to be chiral.
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There are two ways by which enantiomers can be drawn
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two lines are used to used to represent two of the bonds to the chirality center in the plane of the paper, – one bond as a solid wedge coming out of the paper; and – the fourth bond as a hatched wedge projecting back from the paper. What way of drawing enatiomers is this?
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Fischer projection formula was devised by in what year?
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– The point of intersection of two perpendicular lines are used to represent the chirality centre, – horizontal lines represent the bonds that project out of the plane of the paper toward the viewer; and – vertical line represent the bonds that project back form the plane of the paper away from the viewer. – The carbon chain is drawn vertically with C- 1 at the top
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To distinguish between two enantiomers, a system of nomenclature that indicates the configuration (arrangement) of the groups (or atoms) about the chirality center was devised by three chemist named?
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The first step in the naming system; is to rank the groups (or atoms) that are bonded to the chirality center in order of priority.
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The priority depends on the atomic number of the atoms directly attached to the chirality centre.
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The greater the atomic number the higher the priority
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In Naming Enantiomers: R ands S system of Nomenclature. What does r and s mean in latin and english
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A chirality center is also refer to as
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Enantiomers can be named as?
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the R and S system of nomenclature of stereoisomers now known as?
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-----is a phenomenon observed when a molecule rotates the plane of polarization.
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Study Notes
Enantiomeric Excess (ee)
- Enantiomeric excess (ee) is used to quantify the difference when a mixture contains more of one enantiomer than the other.
- ee is expressed as ((percentage of R enantiomer - 50) × 100) / 50.
Exercises
- A mixture containing 60% R enantiomer and 40% S enantiomer has a 20% enantiomeric excess of R.
- In a sample of carvone, if the optical rotation is (-)23° and the specific rotation of (S)-carvone is (+)61°, the enantiomer in excess is S, and its ee is 63.3%.
- The percentage of (R)-carvone is 18.5%, and (S)-carvone is 81.5%.
- If the specific rotation of (S)-(+)2-bromobutane is +23.1° and a sample has an observed specific rotation of +9.2°, its optical purity is 40%.
- A mixture of 3g of (+)-2-bromobutane and 2g of (–)-2-bromobutane has a rotation of +12.21°.
Geometric Isomers
- In an alkene, if hydrogens are on the same side of the double bond, it is the cis isomer; if they are on opposite sides, it is the trans isomer.
- The cis-trans system can be unreliable and may not always work; it is safer to start from scratch in each case.
Heterocyclic Compounds
- Heterocyclic compounds contain heteroatoms like nitrogen, oxygen, or sulfur within the fused ring structure.
- They can have unique properties and reactivities.
Stereochemistry
- Stereochemistry is the study of stereoisomers, which are isomers with atoms connected in the same way but differing in spatial arrangement.
- Optical isomers contain chirality centers, where a carbon atom is bonded to four different atoms or groups of atoms.
- A carbon atom bonded to four different atoms or groups of atoms is known as a chirality center or stereogenic center.
Polarimeter and Specific Rotation
- A polarimeter is an instrument that measures the amount an optically active compound rotates plane-polarized light.
- Specific rotation is the number of degrees of rotation caused by a solution of 1.0 g of the compound per mL of solution in a sample tube 1.0 dm long at a specified temperature and wavelength.
Heterocyclic and Aromatic Compounds
- Heterocyclic compounds have rings made of carbon atoms and one or more heteroatoms like oxygen, nitrogen, sulfur, and phosphorus.
- Aromatic compounds contain a benzene ring structure and exhibit unique stability due to resonance.
- Polynuclear compounds, also known as polycyclic aromatic hydrocarbons, are organic compounds composed of two or more benzene rings that are fused together.
Unique Properties of Carbon
- Carbon forms a large number of compounds due to its unique properties:
- Tetravalency of carbon
- Ability to form double or multiple bonds with another carbon
- Strong covalent bonds with other elements like nitrogen, oxygen, sulfur, halogens, and phosphorus
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Description
This quiz covers the properties and reactivities of heterocyclic polynuclear compounds, which contain hetero-atoms like nitrogen, oxygen, or sulfur within the fused ring structure. Learn about the unique characteristics of these compounds and how they behave. Test your knowledge and understanding of these complex molecules.