CHEMISTRY MODEL QUESTION PAPER

SET 2

1. One gram mole of a substance contains 6.023 x 1023 molecules
a) Find out the number of molecules in 2.8 g of Nitrogen (1)
b) Which is heavier, one SO2 molecule or one CO2 molecule (1)
c) Under identical conditions of temperature and pressure, equal volume of
all gases contains equal number of molecules. Name the law (1)
d) An organic compound contain 52.2% Carbon, 13 % hydrogen and the rest Oxygen.
Find the empirical formulae of the compound (2)
2. a) The electronic configuration of an element with atomic number 7 is given below
1S2 2S2 2Px
2 2Py
1 2Pz
0
Do you agree with the above configuration. Justify (2)
b) Sketch the shape of S and P orbitals (1)
c) Write down the values of n, l, m and s for an electron in 3d orbital (1)
3. a) The properties of the elements are periodic functions of their atomic number.
Name the law. (1)
b) Which is bigger Cl or Cl- Why? (2)
4. a) Fill in the blanks (2)
Molecule
Hybridisation Shape
CH4 …………….. Tetrahedral
PCl5 SP3d ……………
BeF2 Sp ……………
………….. SP2 Trigonal Planar
b) Bond order gives an idea about the stability of the molecule. Calculate the bond order
of the following species and arrange them in the increasing order of bond length
O2, O2
+, O2
- (3)
OR
5. a) Using VSEPR theory explain the shape of Water molecule (2)
b) H2O is a liquid, while H2S is a gas a room temperature. Why? (1½ )
c) Which has higher dipolemoment NH3 or NF3? Why? (1½ )
6. a) Give vanderwaal’s equation and explain the terms. (2)
b) Arrange in the increasing order of viscosity
Honey, water, kerosene (1)
c) How is viscosity dependent on temperature (1)
7. a) Energy of an isolated system always remains constant.
Write the mathematical equation for the first law of thermodynamics (1)
b) Entropy of water is higher than that of ice. Give reason (1)
c) Classify the following as Extensive and Intensive properties
Temperature, Internal energy, density. Enthalpy (2)
8. a) PCl5 à PCl3 + Cl2 ΔH = negative.
What is the effect of temperature and pressure on the above equilibrium (2)
b) Write the conjugate acid – base pair
HCO3
-, HS- (2)
c) What happens when HCl gas is passed through a saturated solution of NaCl?
Which is the effect behind it? Define. (2)
9. a) Calculate the oxidation state of underlined atom
KMnO4, Cr2O7, H2S, NH3 (2)
b) Identify the oxidizing and reducing agent
CuS + O2 à Cu + SO2
c) In the above equation which has undergone oxidation and reduction (1)
10. a) Name the different types of Hydrides (1)
b) Name the isotopes of Hydrogen (1)
c) What is permanent hardness? How can it be removed? (2)
11. a) What are the similarities between Li and Mg? (2)
b) What is washing soda? How can it be prepared? (3)
12. a) What do you understand by (i) inert pair effect (ii) Catenation (2)
b) Explain the structure of Diborane (2)
13. a) Write the IUPAC names of the following compounds
(i) CH3 CO CH2 CH2 CH2 COOH
(ii) CH ≡ C ─ CH = CH ─ CH3 (2)
b) Name the test used (i) to detect the presence of Nitrogen in an organic compound (1)
(ii)to estimate Nitrogen in an organic compound. (1)
14. a) Complete the following (2)
(i) CH3 ─ CH = CH2 + HBr à ……………………………
(ii) 2CH3 ─ Cl + Na à ………… + …………….
b) Represent the two geometrical isomers of 2- butane (2)
c) How will you convert benzene to Nitro benzene (1)
15. a) What is photochemical smog? How can it be controlled? (1)
b) What is BOD ? (1)