Materials from Molecules

Question 1

Identifying the non-metallic element

Answer 1

Make sure it is an element and NOT compound,

Question 2

Non-metallic boiling point

Answer 2

Generally lower

Question 3

Weak intermolecular bond boiling point

Answer 3

Weak intermolecular bond = low boiling point

Question 4

How to identify triple covalent bonds

Answer 4

Undergo the electron dot diagram, create structural diagram from that, then count the amount of bonds

Question 5

How to figure out how many lone pairs of electrons a molecule has

Answer 5

Undergo the electron dot diagram, create structural diagram from that, then count the amount of lone pairs (electrons that are not connected to another)

Question 6

Formula of compounds

Answer 6

Undergo the dot diagram, figure out how many electrons the initial element needs to become stable

Question 7

Ball and stick model

Answer 7

3D model, shows the ball(s) and stick(s)

Question 8

Lewis diagram

Answer 8

Line diagram

Question 9

Space filling model

Answer 9

Squished version of the ball and stick model

Question 10

Structural formula

Answer 10

2D version of the ball and stick model

Question 11

Linear

Answer 11

1 bonding pair

Question 12

Pyramidal

Answer 12

3 bonding pairs

Question 13

Tetrahedral

Answer 13

4 bonding pairs

Question 14

V shaped

Answer 14

2 bonding pairs

Question 15

How to identify polar

Answer 15

If the molecule’s overall electronegativity is uneven and/or not symmetrical

Question 16

Intermolecular bonding : Dipole-dipole

Answer 16

Force of attraction between permanent dipoles of different molecules (electrostatic attraction)

Force of attraction between oppositely charged ends of polar molecules

Second strongest

Question 17

Intermolecular bonding : Dispersion

Answer 17

Forms between molecules as they move close and cause inter dipoles to for, and a force of attraction between molecules exists

Weakest

Question 18

Intermolecular bonding : Hydrogen

Answer 18

Force of attraction betwenn permanent dipoles of different molecules where the dipole charge is more pronounced due to greater electronegativity
eg. H & N, O or F

Strongest

Question 19

How bonding of carbon in graphite and diamond affects : Electrical conductivity

Answer 19

Diamond
- each C atom bonds to other C atoms in tetrahedral latices
- No charged particles formed or amiable to carry charge
Graphite
- Each C atom bonds to 3 other C atoms, leaving 1 electron unbonded & delocalised; charged particle free to carry charge

Question 20

How bonding of carbon in graphite and diamond affect : Hardness

Answer 20

Diamond
- tetrahedral latttice structure, all bonds convalent - very strong
Graphite
- Planer lattice with dispersion forces between layers; len force required to overcome intermolecular forces

Question 21

what is electronegativity?

Answer 21

Tendency of atoms to attract shared electrons when forming chemical bonds

Question 22

How does the electronegativity of the elements of the third period change going across the period from sodium to chlorine?

Answer 22

Increases across period, to chlorine

Question 23

How to identify non-polar

Answer 23

If the molecule’s overall electronegativity is even and/or symmetrical

Question 24

What does the empirical formula look like?

Answer 24

n(c) n(h)
__ : __
12.0 1.0

Question 25

What is the molar mass of methadone? (molecular formula of C21H27NO)

Answer 25

(12 x 21) + (1 x 27) + 14 + 16
= 252 + 27 + 14 + 16
= 309 g/mol

Question 26

Sodium hydroxide formula

Answer 26

NaOH

Question 27

NaOH molar mass (M) :

Answer 27

23 + 16.0 + 1.0

= 40 g/mol

Question 28

RAM formula

Answer 28

RAM = ((( x axis ) x ( y axis )) + (( x axis ) x ( y axis )))/100

Question 29

The element with the highest electronegativity in period 3?

Answer 29

Cl

Question 30

The element, in ground state, which only 2 occupied electron shells and 3 valence electrons

Answer 30

B