Shapes Of Molecules Flashcards Preview

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Flashcards in Shapes Of Molecules Deck (15):
1

Effect of lone pair in shape of molecule

Bond angle decreases by 2.5 degrees per lone pair

2

Tetrahedral

4 bonded pairs
109.5 degree Bond angle

3

Pyramidal

3 bonded pairs
1 lone pair
107 degree Bond angle

4

Trigonal planar

No lone pairs
120 angle
3 electron pairs

5

Linear

2 electron pairs
180 angle

6

Octahedral

6 electron pairs
90 degree

7

Electronegativity

An atoms ability to attract electron pair in a covalent Bond
Decreased down groups and increases across periods

8

Symmetrical polar bonds

Cancel each other out so no overall dipole and is non-polar

9

Dipole

Difference caused by shift in electron density in bond

10

Induced dipole dipole

Electrons in charge cloud, more likely to be more to one side than another so have temporary dipole
Temporary dipole can cause another temporary dipole in opposite direction so attracted
Larger molecules have larger electron cloud so stronger induced dipole
Weak induced dipole keep I2 in molecular lattice

11

Permanent dipole dipole

Slight positives and negative charges cause weak electrostatic attraction between molecules

12

Hydrogen bonding

Only happen when hydrogen covalently comes to fluorine, nitrogen or oxygen
Hydrogen has high charge density and other are very electronegative
Bond polarised that weak bond forms between hydrogen and lone pair of electrons

13

Effect of more electrons

Stronger induced dipole interactions

14

Polar bond

In covalent bonds between 2 atoms of different electronegativites bonding electrons pulled to more electronegative atom
Difference in electronegativity cause permanent dipole

15

Simple covalent Molecules behaviours

Low melting and boiling points
Polar molecules soluble in water
Don’t conduct electricity