Chemical Bonding + Structure

Question 1

what is an ionic bond

Answer 1

• electrostatic attraction between oppositivley charged ions
• transfer of electrons
• polarity difference greater than 1.7
• usually metal + non metal (cations and anions)

Question 2

what is a covalent bond

Answer 2

• electrostatic attraction between a pair of electrons and a positively charged nuclei
• sharing of electrons
• usually nonmetal+ nonmetal

Question 3

what is metallic bond

Answer 3

• negatively charged metal ions are attracted to delocalized electrons
• metal + metal

Question 4

what are ionic compounds

Answer 4

are formed when electrons are transferred from one atom to another to form ions with complete outer shells of electrons
- consist of ions held tightly together in attic structures by ionic bonds

Question 5

what are polyatomic ions

Answer 5

ions containing more than one elements

Question 6

CATIONS

Answer 6

metals LOSE electrons to form positive ions

Question 7

ANIONS

Answer 7

non-metals gain electrons to form negative ions

Question 8

how can charge be predicted

Answer 8

accorrding to position on periodic table

- transition metals can form more than one charge

Question 9

properties of ionic compounds

Answer 9

• solids
• lattice structure
• high melting point + boiling point
• low volatility
• do NOT conduct electricity in solid state
• soluble in water
• neutrally charged due to balance of positive and negative ions

Question 10

what is the goal of a covalent bond

Answer 10

octet rule/stability: to achieve a full shell of valance electrons

Question 11

WHAT IS A MOLECULE

Answer 11

a group of atoms held together by covalent bonds

Question 12

what happens as more bonds are added

Answer 12

bond length decreases and bond strength increases

Question 13

what is electronegativity

Answer 13

the tendency of an atom in a molecule to attracted a shared pair of electrons towards itself

Question 14

what is polarity

Answer 14

polar bonds form when two atoms bonded together have different electronegativity values (UNEQUAL SHARING)

Question 15

what is VSEPR

Answer 15

VALANCE SHELL ELECTRON PAIR REPULSION: the total # of electron domains determine the geometrical arrangement by maximum repulsion

• ELECTRONS ARRANGE THEMSELVES AROUND A CENTRAL ATOM SO THA THEY ARE AS FAR APART AS POSSIBLE

Question 16

Linear

Answer 16

electron domains: 2 (2 atoms bonded to central atom)

angle: 180

Question 17

Bent/V-shaped

Answer 17

electron domain: 3 (2 atoms bonded to central atom with one or two un paired electrons)

angle: 105

Question 18

Trigonal Planear

Answer 18

electron domain: 3 ( 3 atoms bonded to central atom)

angle: 120

Question 19

trigonal pyramidal

Answer 19

electron domain: 4 (3 atoms and an unbonded pair bonded to central atom)

angle: 107 or less than 109.5

Question 20

tetrahedral

Answer 20

electron domain: 4 (4 atoms bonded to central atom)

angle: 109.5

Question 21

having polar bonds does not equal a polar molecule

Answer 21

symmetrically also is taken into account

Question 22

what are intermolecular forces

Answer 22

the physical properties of molecular substances that result from different type of forces between their molecules

Question 23

types of intermolecular forces

Answer 23

• van der waal forces
• london forces (dispersion forces)
• dipole-dipole forces
• hydrogen bonding

Question 24

what are london dispersion forces

Answer 24

• temporary dipoles due to fluctuating electrical field
• electrons can be unevenly spread which lead stop temporary dipoles

trend: increase with increasing molecular mass

Question 25

factors that affect the magnitude of london forces

Answer 25

- number of electrons - size and volume of electron cloud - shapes of molecules

Question 26

what are dipole-dipole forces

Answer 26

- when dipoles attract (usually in polar molecules) | - weaker than covalent bonds

Question 27

what are hydrogen bonds

Answer 27

- a strong type of dipole-dipole - when hydrogen bonds to a small, highly electronegative element F, N

Question 28

strength of the forces

Answer 28

van der waal

Question 29

melting + boiling point

Answer 29

are an indication of the strength of the intermolecular forces

Question 30

m+ b points of covalent bonding

Answer 30

STRONG

Question 31

m+ b point of ionic and metallic bonding

Answer 31

strong due to ionic attraction

Question 32

the weaker the attractive forces....

Answer 32

the more volatile (boiling point) the substance

Question 33

m/b point of intermolecular forces

Answer 33

h bonding > dipole-dipole> london forces

Question 34

what is conductivity

Answer 34

substance must posses electrons.ions free to move

Question 35

covalent bond conductivity

Answer 35

WEAK CONDUCTORS UNLESS ABLE TO IONIZE SOLUTION

Question 36

Solubility

Answer 36

"Like dissolves like" | polar substances are more soluble in water and less soluble in non-polar substances