Question 1
Hydrazine, N2H4, is a precursor for multiple pharmaceutical compounds.
Which of the diagrams below illustrate the most likely structure and bond angle of hydrazine?
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DP IB Chemistry: HL
Topic Questions
4.2 Resonance, Shapes & Giant Structures
Question 2
Two boron-containing species, boron trifluoride (BF3) and the borohydride ion (BH4-), have different molecular shapes.
What are the shapes around the boron atom in these molecules?
|
|
boron trifluoride (BF3) |
borohydride ion (BH4−) |
|
A |
pyramidal |
tetrahedral |
|
B |
pyramidal |
square planar |
|
C |
trigonal planar |
tetrahedral |
|
D |
trigonal planar |
square planar |
Question 3
Graphite has a structure containing layers of carbon atoms in hexagonal rings.
Why is graphite a good conductor of electricity?
It has delocalised ions which can move and carry charge
It has delocalised electrons which are mobile
There are only weak London forces between the layers
Each carbon atom in the layers has only three covalent bonds
Question 4
What is the correct bond angle in a trigonal planar molecule?
107°
120°
180°
109.5°
Question 5
Which of the following is correct?
|
|
Shape of SF6 molecule |
Bond angle in SF6 molecule |
|
A |
Octahedral |
90° |
|
B |
Square planar |
90° |
|
C |
Trigonal bipyramidal |
120° |
|
D |
Tetrahedral |
109.5° |
Question 6
Which statement about the physical properties of substances is correct?
Covalent structures always have high melting points
Metals only conduct electricity when solid
Metals always have high melting points
Ionic substances conduct electricity when liquid
Question 7
Which of the following statements about graphite is correct?
The bond angle in graphite is 109.5 o
There are only London forces between the layers of graphite
Graphite has a higher melting point than diamond
Graphite is soluble in water
Question 8
Which of the following is the correct resonance hybrid structure of the carbonate ion, CO32-?
Question 9
Which of the following is correct?
|
|
Shape of CCl4 molecule |
Bond angle in CCl4 molecule |
|
A |
Octahedral |
90° |
|
B |
Square planar |
90° |
|
C |
Trigonal bipyramidal |
120° |
|
D |
Tetrahedral |
109.5° |
Question 10
Which substance is described in the table below?
|
Melting point |
Electrical Conductivity |
Solubility |
|
Very high |
Non-conductor |
Does not dissolve |
Silicon dioxide
Buckminsterfullerene
Graphite
Sodium chloride
