304 Flashcards
Donation of an electron by one atom to another is normally occured in:
Ionic bonds
Attractive forces between molecules:
Intermolecular
Secondary
Van der waals
(All of the above)
Atoms are held together by primary bonds such as:
Ionic
Covalent
Coordination
(All of the above)
NONPOLAR covalent bonds can be obtained when the electro negativity between two atoms in a molecule is
Lower than 0.5
Hydrocarbons that contain a double bond between 2 carbon atoms are called
ALKENES. ENES
Unsaturated hydrocarbons contain
CC double bonds
CC triple bonds
Alcohols react with acids to form
Esters
Diacids are monomers for synthesis of
Polyesters
Polyamids
Hydrogen bonds is the most important interaction bond in organic molecules and polymers
FALSE.
Electro negativity can be directly calculated
NO. FALSE
Electro negativity can be calculated from
Atomic / molecular properties
Ionization energy
Electron affinity
Ionization energy is the minimum energy release to remove the most loosely bound electron of an isolated gaseous atom, positive ion, or molecule
FALSE
Electron affinity is the amount of energy required when an electron starches to a neutral atom or molecule in the gaseous state to form an anion
FALSE
Electronegativity increaes from right to left on periodic table
FALSE
C-F is less polar than C-H
False
Coordination bond is an alternate ionic bond
False
Coordination bond can be formed by
Sharing of electron pair from a single atom
Hydrocarbons contain carbon, hydrogen, and oxygen
False
ALKANES HAVE THE FORMULA
CnH2n+2
NAME OF (hexagon)
CYCLOHEXANE
Allene’s have
Carbon carbon triple bond
Aromatic compounds must be
Cyclic
Conjugated
Obey huckels rule
NAPTHANE
8 bi-electrons
HEXAGON WITH COOH
Benzoic acid
AMIDE GROUP (R,R’,R’’)
AMIDE GROUP
Compound (UFO) N R1R2
Secondary amine
ESTER GROUP
2 R, C=O
Alcohols react with isocyanates to form urethanes
FALSE
Stoichomerty ratio is the number relationship between
Reactive groups in a reaction
Polyurethanes can fort
Hydrogen bond and thus be very crystalline
Polyester is the first thermo setting resin
FALSE
In thermoplastic materials, the chains do share bonds w surrounding chains
FALSE
Unsaturated diacids procife unsaturation (double bond) as reactive cross linking cite
TRUE
Epoxy ring reacts with amine to open the ring
TRUE
Thermoset with fully reacted groups ensure the max stability
TRUE
Dimensional stability of thermosets its lower than thermoplastics
FALSE
Chemical resistance of thermosets is lower than amorphous
FALSE
Hear can remelt thermosets
FALSE
Which of the following compounds can make thermosets
Epoxy
polyester
Phenolic
Acids react with alchohols to produce polyester
FALSE
NAME OF HEXAGON CH-CH2
Vinyl toulouene
Aliphatic amines react with epoxy at lower temp than aromatic amines
TRUE
Partially cured thermosets with unreacted groups can lead to property changes over time
True
Reactive modifiers normally used with thermoset polymers
Improve impact
Improve adhesion
Lower exotherm
Thixotropic agents increase viscosity of incited thermosets
TRUE
RXN of diisocyanates with diols produces polyurethanes
TRUe
Phenolic thermosets can be obtained by rxn of
Phenols and formaldehydes
