1) Explain the formation of following molecules using Valence Bond Theory
i) H2 ii) Cl2 (AS1) 4 Marks
2) Explain the formation of Covalent bonds of F2, O2 molecules. AS1 4 Marks
3) Draw the diagrams showing the arrangement of electrons in the following molecules
a) Calcium oxide (CaO) b) Methane (CH4)
c) Boran triflouride (BF3) d) Fluorine (F2) (AS1) 4 Marks
4) Indicate by means of figures how single, double and triple bonds are formed? (AS5) 4 Marks
5) The electronic configurations of the atoms x and y are 2, 8, 1 and 2, 8, 7 respectively (AS1) (AS4) 4 Marks
I) Which atom forms anion? Why?
II) Which atom forms cation? Why?
III) To which blocks X and Y elements belong to?
IV) Write the formula of the molecule formed by X and Y atoms.
6) The electronic configuration of elements X and Yare 2, 8, 3 and 2, 6 respectively (AS1) (AS4) 4 Marks
I) Which atom forms anion?
II) Which atom forms cation?
III) What is the valency of atom 'X'?
IV) Write the formula of molecule formed by X and Y atoms.
7) From Na, Mg, O, Cl, N, Ca among which elements there is a possibility of formation of Ionic bond? Explain giving reasons (AS1) 4 Marks
8)
Observe the figure given and answer the questions (AS4) 4 Marks
I) How many valence electrons are there in Carbon atom?
II) What is the valency of Hydrogen?
III) How many covalent bonds are there in this molecule?
IV) What is the bond angle between H C H?
9) The properties of NaCl, HCl and C2H6 are given in the below table. Observe them and answer the following questions. (AS4) 4 Marks
|
Property |
NaCl |
HCl |
C2H6 |
|
Physical appearance |
White crystalline solid |
colourless gas |
colourless gas |
|
Type of bond |
Ionic |
polar covalent |
covalent |
|
Melting point |
801°C |
-115°C |
-183°C |
|
Solubility |
Soluble in polar solvents like water |
soluble in polar solvents like water and to some extent non-polar |
soluble in non-polar solvents |
|
chemical activity |
highly reactive in polar solvents and reactions are instantaneous |
moderately reactive |
slow or very slow at room temperature |
i) Which is Ionic compound? Write the formula.
ii) Write about solubility of Ionic compounds.
iii) Chemical Activity of which substance is less?
iv) Draw the diagram of HCl molecule.
10) What are the differences between ionic bond and covalent bond? (AS1) 4 Marks
11) Explain the bonds in NH3 molecule using hybridisation? (AS1) 2 Marks
12) Explain about octet configuration. (AS1) 2 Marks
13) Why do the atoms of elements combine to form molecules? (AS1) 2 Marks
14) Explain why the bond angle in water molecule will be 104° 31' according to VSEPRT theory? (AS1) 2 Marks
15) Explain about co-ordination number. What are the co-ordination number of Na+ and Cl - ions in NaCl crystal?
16) Explain the formation of CH4 molecule according to covalent bond. (AS1) 2 Marks
17) Explain the formation of HCl molecule using hybridization. (AS1) 2 Marks
18)
With the help of above diagram answer the questions (AS4) 2 Marks
i) How many valence electrons are present in Oxygen atom?
ii) Which is the bond between Oxygen atoms?
19) Imagine what happens if chemical bond doesn't form? (AS2) 2 Marks
20) Imagine what happens if electron transfer is not possible in between of atoms. (AS2) 2 Marks
21) Draw the figure of BF3 molecule formed by hybridization. (AS5) 1 Mark
22)
What does the above figure represent? (AS5) 1 Mark
23)
What does the adjacent figure represent? (AS5) 1 Mark
24) Draw the Lewis dot structure of Al atom. (AS5) 1 Mark
25) Draw the atomic structure of BF3 and indicate its bond angle. (AS5) 1 Mark
26) Draw the figure of BeCl2 molecule which has linear structure and identify the bond angle. (AS5) 1 Mark
