T/f

Question 1

Steric effect is mutual repulsion of atoms having inert gas configuration of electrons

Answer 1

True

Question 2

A Lewis acid accepts a pair of electrons

Answer 2

True

Question 3

Changing all of the stereogenic centers (e.g. R to S) in a chiral molecule will give a diastereomer

Answer 3

False but it will give an enantiomer

Question 4

A meso compound has stereogenic centers

Answer 4

True

Question 5

The atomic number of beryllium is 5

Answer 5

False

Question 6

Resonance forms are structures of rapidly interconverting molecules

Answer 6

False

Question 7

A chiral reagent or method is always required to recognize/separate enantiomers

Answer 7

True

Question 8

Z-2,3-dibromo-2-butane and E-2,3-dibromo-2-butane are disatereomers

Answer 8

True

Question 9

The density of substances which gloat on water is usually less than 1.0

Answer 9

True

Question 10

Intermolecular attraction of alkanes molecules is due to London forces

Answer 10

True

Question 11

Delta G is positive for an endothermic reaction

Answer 11

True

Question 12

Amide anion (NH2 minus) is less basic than hydroxide anion

Answer 12

True

Question 13

About 150 to 200 kcal/mole of energy are available at toom temperature

Answer 13

False

Question 14

The net dipole of dichloromethane is aligned with a carbon-chlorine bond

Answer 14

False

Question 15

A completely pure organic combined may have different physical properties depending on whether it was made by chemists or isolated from nature

Answer 15

False

Question 16

Bronsted- Lowry acids donate a proton

Answer 16

True

Question 17

A carbocation intermediate in a reaction is a transition state

Answer 17

False

Question 18

The pKa of pure water is about 7

Answer 18

False

Question 19

The structure of a molecule determines all of its physical and biological properties

Answer 19

True

Question 20

Overlap of two sp2 orbitals in a double bond generates a sigma molecular orbital

Answer 20

True

Question 21

A Lewis acid is a nucleophile

Answer 21

False

Question 22

Changing all of the chiral centers (e.g R to S) in a chiral molecule will give an enantiomer

Answer 22

True

Question 23

A meso compound is achiral

Answer 23

True

Question 24

A 80:20 mixture of enantiomers has an optical purity of 60%

Answer 24

True

Question 25

A 80:20 mixture of enantiomers has an enantiomeric excess of 60%

Answer 25

True

Question 26

A chiral reagent or method is always required to separate enantiomers

Answer 26

True

Question 27

The S,2 reaction has a carbocation intermediate

Answer 27

False

Question 28

Delta G is negative for an endothermic reaction

Answer 28

False

Question 29

Resonance forms are not rapidly interconverting molecules

Answer 29

True

Question 30

Resonance forms are structures of rapidly interconverting molecules

Answer 30

False

Question 31

Compounds containing more than 65% halogen usually have a density rho > 1.0

Answer 31

True

Question 32

The atomic number of an atom is the total mass of neutrons and protons in the nucleus

Answer 32

False

Question 33

A radical intermediate in a reaction is accurately described as a transition state

Answer 33

False

Question 34

The net dipole of chloroform is not aligned with any carbon-chlorine bond

Answer 34

True

Question 35

Elemental Iodine (I2) reacts slowly with alkanes to give alkyl iodides

Answer 35

False

Question 36

The energy needed to break a carbon-hydrogen single bond is about 15-20 kcal/mole

Answer 36

False

Question 37

All Bronsted-Lowry acids are also Lewis acids

Answer 37

True

Question 38

The net dipole of carbon tetrachloride is zero

Answer 38

True

Question 39

Overlap of two sp orbitals in a triple bond generates a sigma molecular orbital

Answer 39

True

Question 40

The energy needed to break a carbon-hydrogen single bond is about 100 kcal/mole

Answer 40

True

Question 41

Chloroform has a density r > 1.0

Answer 41

True

Question 42

The net dipole of methane is zero

Answer 42

True

Question 43

Cis- 1,2 - dichlorocyclopropane and trans-1,2,- dichlorocyclopropane are diastereomers

Answer 43

True

Question 44

Tautomers are structural isomers with respect to each other

Answer 44

True

Question 45

The atomic number of an atom is the total number of protons and neutrons in the nucleus

Answer 45

False

Question 46

The E1 reaction has a carbocation intermediate

Answer 46

True

Question 47

The zaitsev (saytzeff) rule factors formation of more highly substituted double bonds

Answer 47

True

Question 48

Oxidation is always defines as the process of adding oxygen atoms

Answer 48

False