shapes of molecules Flashcards
no. of bonding pairs in linear , no. of lone pairs
2….0
no. of bonding pairs v-shaped, no. of lone pairs
2…..2 or 1
no. of bonding pairs t-shaped, no. of lone pairs
3….2
no. of bonding pairs trigonal planar, no. of lone pairs
3…0
no. of bonding pairs trigonal pyramidal, no. of lone pairs
3……1
no. of bonding pairs tetrahedral and square planar, no. of lone pairs
4….0
no. of bonding pairs trigonal bipyramidal, no. of lone pairs
5….0
no. of bonding pairs octahedral, no. of lone pairs
6…0
linear bond angle
180’- both bonds equally repel each other therefore linear
v–shaped bond angle
120’, or if 2 lone pairs 105’
t-shaped bond angle
90’
trigonal planar bond angle
120’
tetrahedral
109.5
trigonal pyramidal
107’
square planar
90’
trigonal bipyramidal
90’ &120’
octahedral
90’
worth of a lone pair
around 2.5
Fluorine and iodine are elements in Group 7 of the Periodic Table. Explain why iodine has a higher melting point than fluorine.
Iodine has more electrons / iodine is bigger (atom or molecule) / iodine has bigger Mr / bigger surface areaStronger / more van der Waals forces / vdw / London / temporarily induced dipole / dispersion forces between molecules
State the strongest type of intermolecular force in a sample of NHF2
Hydrogen bonds
A molecule of NHF2 reacts with a molecule of BF3 as shown in the following equation. NHF2 + BF3 —–> F2HNBF3State the type of bond formed between the N atom and the B atom in F2HNBF3 Explain how this bond is formed.
Coordinate / dative covalent / dativeLone pair / both electrons/ 2 electrons on N(HF2) donated (to BF3)
