The following equation shows the dissociation equilibrium of PCl5.
PCl5(g) → PCl3(g) ＋ Cl2(g)
The percentage yield of PCl3 varies with temperature.
At 160°C PCl3 yield is 13% and at 300°C yield is100%.
Which of the following rows is correct?
|
|
The reaction is |
Shape of PCl3 molecule |
|
A |
exothermic |
trigonal pyramidal |
|
B |
exothermic |
trigonal planar |
|
C |
endothermic |
trigonal pyramidal |
|
D |
endothermic |
trigonal planar |
Boron trifluoride, BF3, reacts with trimethylamine, (CH3)3N, to form a compound of formula (CH3)3N.BF3.
How may this reaction be written using 3D structures to show the shapes of the reactants and products?
Which of the following statements about graphite are correct?
I and II only
I and III only
II and III only
I, II and III
Which statement below shows the correct information about diamond and silicon?
Diamond is macromolecular and silicon is simple molecular
The bond angles in the two structures are the same
The bond lengths are longer in C-C than in Si-Si
Diamond and silicon both conduct electricity due to delocalised electrons in their structure
How many lone pairs of electrons are there around the chlorine atom in a molecule of chlorine trifluoride, ClF3?
1
2
3
0
Which one of these species has a bond angle of 120°?
H3O+
TlBr32-
BCl3
NH3
Which of the following statements about silicon dioxide is correct?
I and II only
I and III only
II and III only
I, II and III
Ibuprofen is an anti-inflammatory drug that is used for treating pain, fever and inflammation. The structure is shown below.
Ibuprofen
What are the correct bond angles for a and b?
|
|
a |
b |
|
A |
120o |
120o |
|
B |
107o |
109.5o |
|
C |
109.5o |
120o |
|
D |
120o |
109.5o |
Which of the following molecules obeys the octet rule?
BF3
HCN
BeCl2
CS2
Which row in the table is correct?
|
|
Shape of diamond structure |
Melting point of buckminsterfullerene |
Bond angle in graphene |
|
A |
Square planar |
Relatively high |
90o |
|
B |
Tetrahedral |
Relatively low |
107o |
|
C |
Trigonal Planar |
Relatively high |
109.5o |
|
D |
Tetrahedral |
Relatively low |
120o |
