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Flashcards in 2.2 Deck (33)
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1

orbital

region of space where an electron is likely to be found. it can hold 2 electron providing that they are of opposite spin

2

shape and number of s orbitals

spherical, 1 in every level

3

shape and number of p orbitals

dumbbell, 3 in levels 2 and up

4

number of d orbitals

5 in levels 3 and up

5

number of f orbital

7 in levels 4 and up

6

Aufbau principle

Electrons enter the lowest possible energy level

7

Rauls exclusion principle

2 electrons can go in each orbital provided they are of opposite spin

8

Hunds rule of maximum multiplicity

When in orbitals of equal energy electrons will try and remain unpaired

9

Types of intermolecular forces/ physical forces

Induced dipole- dipole interaction
Permanent dipole - dipole interaction
Hydrogen bonds

10

Ionic compounds

Formed between metals and non metals
Electrons are transferred
Giant ionic lattice , very brittle -> dislocation of layers leads to repulsion between similar ions, conduct electricity in solution or molten, soluble in polar solvents vv high melting point

11

Covalent bond

Shared pair of electrons with one electron being supplied by each atom on either side of the bond

12

Dative covalent bond

Shared pair of electrons where both electrons are donated by one atom

13

Why are covalent bonds strong

Electrostatic forces between the shared electrons and the positive nuclei

14

Properties of simple covalent molecules

Don't conduct electricity
Low meting and boiling points due to weak intermolecular forces between molecules soluble in organic solvents but not in water

15

Lone pair

Pair of non bonded electrons

16

properties of giant covalent molecules

Don't conduct electricity, very high melting and boiling points due to strong covalent bonds, in graphite delocalised electrons conduct electrons

17

why do molecules form certain shapes

the shaped adopted by a simple ion or molecule it that which keeps the repulsive forces to a minimum

18

shape and bond angles of a molecule with 2 bonded pairs

180 degrees, linear

19

shape and bond angles of a molecule with 3 bonded pairs

120 degrees, trigonal planar

20

shape and bond angles of a molecule with 4 bonded pairs

109.5, tetarhedral

21

shape and bond angles of a molecule with 5 bonded pairs

120 and 90 trigonal bi-pyramidal

22

shape and bond angles of a molecule with 6 boned pairs

90 octahedral

23

by how much does a lone pair reduce a bond angle

2.5 degrees

24

electronegativity

the ability of an atom to attract the pair or electrons in a covalent bond to itself

25

physical forces

the forces between different molecules within a substance (inter-molecular forces)

26

induced dipole dipole interaction explanation

at any point in time it is possible that the electrons in a molecule are on one side, an instantaneous dipole is produced inducing a weak dipole in nearby molecules creating weak forces between them

27

hydrogen boding

strongest type of intermolecular force. water is very polar-> very strong dipole dipole attraction called a hydrogen bond. h2o can from 2 hydrogen bonds

28

unusual properties of water

higher melting and boiling point than expected, ice is less dense than water so it floats, high surface tension and viscosity

29

why is ice less dense than water

when ice forms molecules form an open lattice keeping the molecules farther apart than when they are liquid

30

why does water have a higher melting/boiling point than expected

the very strong hydrogen bonds between the H2O molecules are much stronger than normal intermolecular forces.