Chapter 5

Question 1

compound

Answer 1

a substance that is made up of 2 or more different elements combined together chemically. eg- NaCl

Question 2

molecule

Answer 2

a group of atoms joined together. the smallest particle of an element or compound that can exist independently. eg- Cl2

Question 3

octet rule exceptions

Answer 3

1. transition metals
2. hydrogen, lithium, beryllium tend to achieve 2 electrons in their outer shell rather than 8.

Question 4

ion

Answer 4

a charged atom or group of atoms

Question 5

ionic bond

Answer 5

force of attraction between oppositely charged ions in a compound. always formed between the complete transfer of electrons from one atom to another.

Question 6

charges of ionic compounds

Answer 6

g1- 1+
g2- 2+
g3- 3+
g4- 4+ or 4-
g5- 3-
g6- 2-
g7- 1-
g8- no ion

Question 7

7 diatomic molecules

Answer 7

hydrogen, nitrogen, fluoride, oxygen, iodine, chloride, bromine

H2, N2, F2, O2, I2, Cl2, Br2

Question 8

transition metals

Answer 8

element that forms at least one ion with a partially filled sublevel. properties:
-have variable valency
-widely used as compounds
-usually coloured compounds

Question 9

exceptions to transition metals

Answer 9

Sc3+, Zn2+ because they do not have a partially filled d sub-level

Question 10

what forms a single bond

Answer 10

when one pair of electrons is being shared between 2 atoms

Question 11

what forms a double bond

Answer 11

when two pairs of electrons are shared between 2 atoms

Question 12

what forms a triple bond

Answer 12

when three pairs of electrons are shared between 2 atoms

Question 13

what shape are all double and triple bonds

Answer 13

linear in shape and single

Question 14

what are the bond energies for single, double, and triple bonds like

Answer 14

single- weakest
double- stronger than single
triple- strongest
~ this is due to sigma bonds being stronger than pi bonds

Question 15

sigma bond

Answer 15

formed by the head on overlap of 2 orbitals

Question 16

pi bond

Answer 16

formed by the sideways overlap of p orbitals

Question 17

how many sigma and pi bonds in each of the 3 bonds

Answer 17

single bond- one sigma bond
double bond- one sigma bond and one pi bond
triple bond- one sigma bond and 2 pi bonds

Question 18

properties of ionic bonds

Answer 18

-contains a network of ions in the crystal
-usually hand and brittle
-high melting and boiling points
-usually solid at room temp
-conduct electricity when in molten state or when dissolved in water

Question 19

properties of covalent bonds

Answer 19

-contain individual molecules
-usually soft
-low melting and boiling points
-usually liquids, gasses or soft solids at room temp
-do not conduct electricity

Question 20

electronegativity

Answer 20

the relative attraction that an atom in a molecule has for a shared pair of electrons in a covalent bond

Question 21

uses of electronegativity

Answer 21

1. predict polarity of covalent bonds
2. predict which compounds are ionic and which are covalent

Question 22

polar covalent bond

Answer 22

a bond in which there is an unequal sharing of the pair(s) of electrons. this causes one side to be slightly positive and the other slightly negative.

Question 23

non-polar covalent bond

Answer 23

a bond in which there is an equal sharing of electrons

Question 24

electronegativity difference greater than 1.7 means

Answer 24

ionic bonding

Question 25

electronegativity difference less and or equal to 1.7 means

Answer 25

covalent bonding

Question 26

electronegativity difference between 0.4 and 1.7 means

Answer 26

polar covalent bond

Question 27

electronegativity difference less than or equal to 0.4 means

Answer 27

non-polar covalent bond

Question 28

exceptions to predicting bonding in compounds

Answer 28

when the shape of the molecule is: 1. linear 2. trigonal planar 3. tetrahedral

Question 29

intramolecular bonding

Answer 29

bonding that takes place within a molecule, i.e. holds the atoms together, i.e. ionic and covalent bonding

Question 30

intermolecular forces

Answer 30

the forces of attraction that exist between molecules, i.e. Van Der Waals forces, dipole-dipole forces, hydrogen bonding

Question 31

Van Der Waals forces

Answer 31

weak attractive forces between molecules resulting from the formation of temporary dipoles (temporary attraction as a result of a shift of electrons) ~ only force of attraction between non-polar molecules ~boiling point increases with atomic mass ~weakest intermolecular bonding

Question 32

dipole-dipole forces

Answer 32

forces of attraction between the negative pole of one polar molecule and the positive pole of another polar molecule. a permanent dipole if formed between 2 polar molecules ~medium strength, therefore average boiling point ~higher boiling point than Van der Waals

Question 33

hydrogen bonds

Answer 33

types of dipole-dipole attraction between molecules in which hydrogen atoms are bonded to nitrogen, oxygen or fluorine.

Question 34

boiling points

Answer 34

affected by intermolecular bonding and molecular mass. if same intermolecular bonding, the larger molecular mass will have the higher boiling point

Question 35

solubility

Answer 35

affected by intramolecular bonding. like dissolves like. water= polar, oil= non-polar